[webui] a bunch of improvements to the recordings section

[Jalle19]

Fixes:

• when a recording switches from "currently recording" to "finished", the "Upcoming recordings" window is now properly updated (the entry disappears) and "Finished recordings" is updated accordingly
• when a recording changes state (e.g. if it's deleted) and it's visible in the EPG filter, the state icon will now be updated accordingly

Improvements:

• the recording details dialog is now opened by pressing an Info icon instead of clicking the row itself
• multiple recordings can now be selected
• the "Add entry" button is now only visible in "Upcoming recordings" since it makes no sense in the other panels. In addition to this, a new button "Abort/unschedule" button is now available.
• a "Delete selected" button is available on the other panels which (wait for it...) deletes the selected recordings
• the Abort/Delete buttons that were previously in the Info details dialog have been removed

Various/dubios:

• removes duplicate check from the general "delete selected" function in tablemgr.js. The button is greyed out unless a selection has been made. I can drop this if you want.

@perexg @adamsutton for review (only tested in Firefox)
@mpmc for testing

Someone with stronger JavaScript-fu will have to refactor some of this crap some day so we can re-use the code a bit more.

[Jalle19]

I'm not absolutely certain whether deleting this has any side effects, does anyone know?

[Jalle19]

I was also thinking of moving the "Download" link from the recording details dialog to the panel buttons. Any thoughts on that?

[mpmc]

@Jalle19 I like that idea! At least then if you know what the selected recording is you wont have to open the info dialog to download it!

A few more suggestions:-

• Add an optional (default is hidden) 'Current programme' column to the Channel / EPG grid to show current programme on the channel.
• Stop the DVB Inputs -> TV adapters tree from collapsing when you hit 'save' - You might want to make this an option as some might prefer it like it is!
• Fix the 'starting around' column in the Auto recorder - You currently cannot set a start time of 00:00. The dropdown defaults to "0" which will then change to "00:00" if you leave "0" selected but once you hit save it vanishes! Oddly if you set your own value say "23:59" and hit 'save' then select it again it automatically takes a few hours off! Wha...? Haha!

[perexg]

Pulled, Merged, Rebased (the extra whitespaces removal) and Pushed to Master. Thanks.