Windows: Updated app icons, deploy Doomsday icon to data/graphics/

ClientWindow was trying to load "doomsday.ico" from a native file but
apparently it wasn't being deployed in the installation.

The app icons now contain sizes 16x16, 32x32, 48x48 and 256x256.

Related to IssueID #1589.
Cleanup
Fixed|Windows|Installer: Path of the app icon file
Merge branch 'master' of ssh://github.com/skyjake/Doomsday-Engine
Refactor|libhexen: Pass mobj-on-top-mobj arguments via Mobj_BoxIterator
libcommon: Continued cleaning up global play-sim variables

The role of each (argument/return-value/etc..) of those remaining is
now much clearer.
Homepage: Updated source package download page for 1.12.1
Fixed|Windows|Installer: Missing app icon in Control Panel
Merge branch 'master' of github.com:skyjake/Doomsday-Engine
Refactor|libhexen: Don't use mobj-check-position vars for mobj-ontop-mobj tests

These two algorithms are not co-dependent. Maintaining state values
used only for mobj-check-position tests merely obfuscates the logic.
libhexen: Removed misleading comment in P_CheckOnMobj()
Refactor|libcommon: Continued cleaning up global play-sim variable usage
libcommon: Cleanup
libcommon: Cleanup
Refactor|libcommon: Pass line attack puff arguments via P_PathTraverse()
Fixed|Builder|OS X: Signing binaries on Mavericks

OS X 10.9 requires that *all* binaries are signed, not just the applications
themselves.

This commit calls codesign on bundled shared libraries, Qt frameworks,
Qt plugins, and other binaries. Also, a number of symbolic links in the
frameworks are recreated since they seem to have gone missing (bug in
macdeployqt?).
Fixed|Builder|OS X: Further fix for signing the bundled Python framework
Builder|Debian: Mark package changelogs as released

Hopefully this will now allow me to upload stable releases to
a Launchpad PPA.
qmake|Ubuntu: Do not install apt repository with package

This was a questionable feature. I would rather have a PPA that the
user can easily add to their apt config if they wish.
Merge branch 'master' into low-latency-input