Fix the changes webView to avoid overlapping text.

Fixes #1642.
Also: tweak the animations a bit to make them less messy
Properly set up KVO for `numberOfPluginsToInstall`

Means the "Install Selected" button is properly disabled when no plugins are ticked for installation
get the manager for the correct trigger

currentTrigger in this context always refers to the first one on the list so it always returns the same manager. selectedTrigger refers to the correct object.
only go into key capture mode if the field is an instance of QSHotKeyField

The old test would prevent you from being able to edit the trigger name.
Merge pull request #1647 from quicksilver/pluginUpdater

Plugin updater
Always show the plugin updater window from the main thread
Merge pull request #1650 from quicksilver/triggerBugs

Trigger bugs
Merge pull request #1664 from quicksilver/pjr/pluginUpdaterMainThread

Show plugin updater from the main thread
use the variable created a few lines earlier
return self from the initializer

Most of the setup messages are being sent to `self`, not `result`.
remove a repeated line

It's called again two lines later.
Merge pull request #1665 from quicksilver/smallFixes

Small fixes
determine the current screen using the search object view

The result controller doesn't get moved over until later in this method.

fixes #1304
Merge pull request #1667 from quicksilver/i1304

determine the current screen using the search object view