TODO

Fields/Column customisation:
 - Option to show/hide fields in the table
 - Option to show additional fields in the HTML Preview
 - Allow customising the fields slurped from the server (e.g. used by plugins)
 - Move to String[] (instead of TreeMap) to store ticket fields. (Memory and speed.)
   (Will have to recreate all tickets whenever new fields are discovered - infrequent.)

Table:
 - Undo from the table (easily undo row deletions)
 - Support copying text (e.g. to paste into Excel)
 - Sort Priority & Severity naturally (not alphabetically)
 - Configurable colour coding (e.g. priority, severity, milestone etc...)
 - Tooltips for truncated fields

Search combo:
 - Allow '|' in field label?

Authentication
 - Disable the 'save password' checkbox (or display a warning) if other users can access the file
   (Looks like would need to implement POSIX and ACL separately. See `Files.getFileAttributeView`.)

Download panel:
 - Show size of file & percentage downloaded

Tools:
 - Find in Tickets: Merge bottom 2 panels, with various view-modes
 - Plot of open tickets over time.
     - Looks to require scraping the HTML timeline in batches (RSS is more verbose). Cache locally.
     - #8728 might help if done, BUT: can't see reopening history, and cached close times might rot.
 - Add Inconsistent keyword detector
 - Add Score field/column; with a configuration dialog to build up scoring formulas

Data sources:
 - Outlook import into user fields (e.g. categories, flag 'notes')
 - Allow user columns which derive from other columns via 'capturing regular expressions'
    - e.g. to extract a "[Topic]" word from the start of a Summary field

BUGS:
 - The "Find Tickets in Text" tool window doesn't update unless the description panel
    changes. I.e. particularly when no table-row is selected, even changing the search
    and updating the table does not update the "Find Tickets in Text" results
 - When saving a search containing an alias, should expand the alias in the saved result.

Code Tidying:
 - Introduce Guava (Immutable collections!)?
    - Probably would want Proguard (to strip out unused library code?)
    - consider also jlink/jpackage nowadays?
 - Create new 'TicketLoader' to more-cleanly manage the 4 loading-tasks, and their cancelling.
 - PropertyChangeListener -> TicketLoaderListener? so the loader listens
   on its multiple tasks, and the frame only listens on one object.

UI Polish:
 - Store column ordering & sizing properly. Column sizes currently 'drift' as the
   window is resized or reopened.
 - Store position of all splitters