Made it so that the 'Back to Turn X' and 'Back to Start' menu items work with .bz2 saves.
disable "show track title feature" for Win-MSVC, Win-MinGw and Mac

(from commit 3440218c0fe5a2a5306ab1c91a6e8f19679f7ef0)
Actually accomplish what a6cf1a69658f1320c3d3eb485ea59c83d2d8f003 was supposed to accomplish.
Remove exposed parameter and private member for bzip2 compression.

For now, just pull it directly from preferences.
Whether we should emulate compress_saves or make compress_saves work the same way is a different concern.
Don't depend on boost::thread when not using libANA
Remove resolutions that are no longer supported
New slicing of the editor backgrounds
Removed unnecessary icon files
Updated artwork for editor brushes
Marked various files as having no translatables.
New artwork for scrollbars
New artwork for scrollbars
Filter for id instead of name; converted some tabs to spaces.
Merge branch 'master' of github.com:wesnoth/wesnoth-old
New artwork for replay controls and commonplace set controls (add/delete, previous/next)
wmllint: Exclude preprocessor directives from [part] children check

This solves spurious errors when attempting to use #ifdef within [part].
Made various strings translatable; disambiguated and split some strings; eliminated an Earth name.
Ran wmlindent.
Split all of the AI-related strings (except for the AI controller's) into a new 'wesnoth-ai' textdomain. Includes a pot-update for 'wesnoth' as a side effect.
pot-update for the rest of the textdomains.