Tidy up feedback model listener.

Kill some unused fields/imports.

Collate plugin PMD reports into one dir.

Tidy up AliasManagerLinker.

In theory make DNS plugin work with IPv6.

Tidy up invite label.

Update PMD to 5.2.2.

Remove the window menu.

This can easily be implemented as a plugin, and as I really don't
fancy fixing it this seems like the next best thing.

Synchronise selection events.

Update build scripts for artifactory.

Gradle version bump.

Tidy up gradle source sets.

This replaces the default source directories (src/main/java, etc)
with our own, instead of just appending ours to the list.

Unit test beep command.

Fix non refreshing away colours.

Add Channel Who Skeleton.

HTTPS some URLs.

Tidy up the developers list a bit.

Set versions on plugins properly.

This makes the plugins include their version in the output file
name, and when used as a dependency.

Also create a dist-versioned directory which accumulates versioned
plugins.

Update addon browser for addons.dmdirc.com move.

Download addons feed over HTTPS.

Issue DMDirc/DMDirc#92

Add active window manager tests.

HTTPS the easter egg.