epubveri for calibre 0.4.0

The last two things Doitsu asked for in post 21, and everything thiago.eec
and he said the next day about 0.3.0 (posts 22 and 23).

• The CSV exports everything again. thiago.eec: "The CVS exports only the
  selected line. Is this intentional? JSON exports the full report." (#22) It
  was not intentional in the sense he means — 0.3.0 asked the table whether
  anything happened to be selected instead of being told what was wanted. The
  menu now has Save all rows as CSV… and, when there is a selection, Save
  selected rows as CSV…; only the one that says "selected" means it. Doitsu
  asked for the same thing (#23).

• An export is offered under the book's own name. Every one used to be
  proposed as epubveri-results.csv, so exporting a selection after the whole
  table landed on the first file, and a folder of them said nothing about which
  book was which. Now:

  Suç ve Ceza (Dostoyevski)-epubveri-all-57.csv
  Suç ve Ceza (Dostoyevski)-epubveri-selected-3.csv
  Suç ve Ceza (Dostoyevski)-epubveri-selected-line-85.csv
  Suç ve Ceza (Dostoyevski)-epubveri-report-63.json
  

  One selected row is named by its line rather than by the count, which
  the owner found by testing the first version of this: exporting the finding
  on line 85 and then a different one both offered selected-1, because "how
  many" says nothing about a selection of one — and that was the collision
  this naming exists to stop. What separates two selections is which rows,
  and for the commonest case, clicking a finding and exporting it, the line is
  exactly that. Two or more rows go back to the count: there is no short way
  to name a set.

  Which book, which part of it, how much. The stem is the file calibre is
  editing — the same one its title bar shows — and calibre's own sanitiser
  keeps a title with a slash or a colon from proposing a path. The scope stays
  a word beside the count, because a number does not say what it counts, and a
  selection of every row would otherwise be offered under the name of the whole
  table. The count is the owner's idea and earns its place the moment a book
  changes between two exports.

  The same book, same scope, unchanged, twice still offers the same name — and
  the save dialog asks before replacing, which is the right place for that
  question.

• Every CSV field is quoted. Doitsu again, who called it "more 'robust'".
  csv quotes for the comma on its own; the case that needs this is the
  semicolon, because a spreadsheet whose list separator is ; — a German
  or Turkish locale — splits an unquoted message containing one straight down
  the middle. A quoted field survives either separator.

• There is a Col column. Doitsu: "Since the Calibre API allows to position
  the cursor by line and column, it'd be helpful, if you added a Column
  column." (#23) It was left out of 0.3.0 on purpose — the number is used
  rather than read, since a double-click puts the cursor on that character —
  and the note recording that decision said the answer if anyone asked would
  be that this is a small change and not a principle. Somebody asked. It sorts
  as a number, like Line.

• The panel's background and the severity colours are two settings now,
  under Appearance in the same page. thiago.eec, of the dark-theme set: "I'd
  rather have the same colors in a dark theme. The new bacground colors are
  better than no color at all, but not as good as the original colors." (#22)

  That is a preference, not a defect, and the owner's call was that it should
  not be settled by argument at all: panel_theme is auto (follow calibre),
  light or dark, and row_colors is theme (follow the panel) or pale
  (the light set in both, as Doitsu's plugins and Sigil use, with the text
  forced dark so it stays readable). Both default to what 0.3.0 shipped,
  so anyone who does not care sees no change; the combinations people asked
  for — a dark panel with pale rows, or a light panel inside a dark calibre —
  are two clicks.

• A clean book no longer opens the panel. His words: "if no problems were
  found, simply display a message box instead of an empty widget." A panel
  that opens to say nothing takes screen space at the moment you are finished
  with it, so the verdict goes in a box and the dock stays shut.

  Minor rather than patch because of that: it is a change in what the plugin
  does, not a fix. A panel that was already open is still refilled — the
  previous book's findings sitting under a clean verdict would be worse than
  either — but it is neither opened nor raised. A book whose every finding is
  hidden by your display settings counts as nothing to list, and the box then
  carries the line saying how many were hidden and where the switch is.

• The status bar says what is happening. He asked for a word while the
  book is being checked, while an update is being looked for or fetched, and
  how that turned out — so there are messages for all four, plus the verdict
  when the run ends. calibre's own show_status_message is used where it
  exists and the bar directly where it does not, since
  minimum_calibre_version claims releases this was not checked in.

  The messages are painted with processEvents, which is not decoration: a
  validation runs on the UI thread, so a line set before the work would
  otherwise appear only once the thing it describes had finished.