Ldapper v0.3.0

The interface is now tested, not just built — and there is a single command
that opens Ldapper against a real directory with nothing to fill in.

The window has tests now

Twenty-four of them, rendering every pane with the shapes the Go side actually
produces. This closes the gap that mattered most: until now the panes were
verified by reading them, and the one time that was not enough, the
application opened to an empty rectangle.

They cover what would break silently — a pane crashing on real data, a
decoded value not reaching the screen, a search batch arriving from Go and not
appearing, a truncated search reported as "found nothing", a filter the server
cannot answer being hidden instead of greyed.

Connect without an account

Plenty of directories allow reading without credentials, and Ldapper had no
way to ask. Anonymous joins NTLM and simple bind in the connection dialog,
and the credential fields step aside when it is chosen.

The connection dialog lists your connections

It had no way to pick among saved connections at all: it silently edited the
first one and read its values once, so opening it a moment early showed
factory defaults over a connection that was already there — with nothing on
screen to explain it. There is now a list of saved connections with a + New
beside them.

One command to see it

make demo

A directory of 2594 entries in Docker, a connection saved for it, and the
application open and pointed at it. Press Connect. make demo-down when done.

Also fixed

• A binding that returns nothing — the Go side failing in a way it could not
  report — left the window silently empty. It now says the directory did not
  answer.
• Errors while loading saved connections were swallowed, producing the same
  unexplained empty form.

Verified

313 Go tests, 24 frontend tests, 37 integration tests against OpenLDAP. The
Windows build compiles and links in CI but still has not been run by hand.