Clean up CMake library specification

The X11 libraries don't need to be specified when doing dynamic linking
Build GLFW as a shared lib on Travis
Travis: Enable APT cache. This should give us a small boost

http://docs.travis-ci.com/user/caching/#Caching-Ubuntu-packages
Travis: Try to cache downloaded files to work around sf.net sucking
armemu: Implement SADD8/SSUB8
Thread: Wait current thread on svc_SleepThread

- Removed unused VBLANK sleep mode
- Added error log for bad context switch
- Renamed VerifyWait to CheckWaitType to be more clear
Merge pull request #319 from yuriks/travis-apt-cache

Travis: Enable caching of dependencies
Merge pull request #318 from bunnei/simulate-thread-sleep

Thread: Wait current thread on svc_SleepThread
Merge pull request #323 from lioncash/saddsub

armemu: Implement SADD8/SSUB8
License change
Added CreateFile to the FS_USER service

Tested with hwtests.
Merge pull request #271 from archshift/createf

Added CreateFile to the FS_USER service
Update README.md
Merge pull request #291 from purpasmart96/license

License change
CFG: Implemented the GetConfigInfoBlk2 function.

Added a "config" file to the CFG process service (CFG:U), and added a few default blocks to it.

Implemented GetSystemModel and GetModelNintendo2DS
CFG:U: Add some data to the 0x00050005 config block.

Seems to allow some games to boot further, thanks @Normmatt for sharing this information
CFG: Refactored how the config file works.

It is now kept in memory as per 3dbrew, all updates happen on memory, then they can be saved using UpdateConfigNANDSavegame.
CFGU: Added block 0x000A0002 to the default savegame file

That's the language id block, we're using LANGUAGE_EN for now. This block allows some games to boot further
CFG: Load the Config savedata file if it already exists.
CFGU: Use an absolute offset in the config savefile blocks