Made core flixel more customizable

- new compiler conditional FLX_NO_PAUSE_SCREEN that disables the default
focus lost screen
- new compiler conditional FLX_NO_SOUND_TRAY that disables the default
sound tray
- all keys used by flixel are now fully customizable via FlxG:
keyDebugger, keyVolumeUp, keyVolumeDown and keyMute
- you can turn off the pausing on focus lost by setting FlxG.autoPause
to false now
Advanced logging system

- You can now define a custom `LogStyle`
- Added `warn()`, error(), `notice()` and `advancedLog()` to `FlxG`
- `warn()`, error(), `notice()` and `log()` support a variable amount of
paramaters. This means that to get an output of "X: 500 Y: 250", you no
longer need to seperate everything with plus signs (log("X: " + this.x +
" Y: " + this.y);), instead you can just have seperate paramters:
log("X: ", this.x, "Y:", this.y); which is more convenient and readable
- Updated all the existing error and warning messages previously using
log()
better fix for setTextFormat() methods in FlxText

Conflicts:
	src/org/flixel/FlxText.hx
Merge pull request #372 from sergey-miryanov/dev

better fix for setTextFormat() methods in FlxText
Added FlxColorUtils

- New class `FlxColorUtils` containing over 30 new colors and the color
constants previously located in FlxG as well as color-related functions
previously located in FlxU added
- For the sake of backwards compatiblity, FlxU and FlxG still contain
the functions / variables, but they are just references to FlxColorUtils
and are documented accordingly
- The new colors have short descriptions from wikipedia pages
Merge pull request #371 from Gama11/dev_log

Advanced logging system
FlxColorUtils uses RGBA and HSBA types now
Made FlxColorUtils function names more accurate
Merge pull request #374 from Gama11/dev_color

Added FlxColorUtils
Renamed to FLX_NO_FOCUS_LOST_SCREEN
Forgot the .nmml template
Merge pull request #359 from Gama11/dev_flxgame

Made core flixel more customizable
Added Reg class and documentation to template
Forgot removing the initialization of the vars
Merge pull request #381 from Gama11/dev_registry

Added Reg class and documentation to template