First step in adding a mod container for instances.

WARNING: will squash.
Minimal changes required for the data to show up in places and not cause segfaults.
Remove more stuff, fix more bugs.
REMOVE.
Nuke bad things and comment on other bad things.
More TODO and FIXME comments.
Move QuickMod queries to the QuickModDatabase
Clean up.
ETags -> etags
Move contents of QuickModSettings into QMDB
Disable automatic and intrusive updates. Remove 'latest version' option.
Moving and renaming. First draft of QuickMods transactions.
Moving and removing of quickmod classes.
Update for Qt 5.3.2
Remove some instance package list methods. Add a package page skeleton.
One more step towards properly nuked quickmods.

* It now has a 'packages' page. It shows what's in the instance.
* Many renames.
* Instance package list is split into list and model.
More quickmod changes

* Removing and reverting versions
* A placeholder quickmod icon
* Rework of version internals -- using version ID for identification and version name for display
Add a ghetto way to add mods to the transaction

* Short-circuit QuickModBrowsePage checkbox logic to operate on top of the current transaction.
* Add ability to switch between pages from within pages (used for the package install button).
* Now missing only applying transactions.
First work on getting installation back
Harden last change against hypothetical segfaults :)