Increment version number to v2.57

As we are using odd numbers for dev versions and even numbers for
release versions, this will eventually merge into master as v2.58.
Flixel Community official website URL instead of Github pages

Replaced flixelcommunity.github.com with flixelcommunity.org.
Move all classes to their new locations

... assets too.
Update code to match moved classes

Edited both package names and import statements so that they now point
to the correct, new locations of the classes. Some import statements
were removed since classes now shared the same package, other import
statements had to be added since the classes were no longer in the same
package.

Had to change the following properties from `internal` to `protected`
after the classes that used them had to change package:

 * Input::_lookup
 * Input::_map
 * Input::_total

Had to change the following properties from `internal` to `public`
after the classes that used them had to change package:

 * FlxBasic._ACTIVECOUNT
 * FlxBasic._VISIBLECOUNT
Update paths for assets

Sadly, the paths are relative, but at least they are reliable.
Rename `FlxAnim` to `FlxAnimation`

Also updated any references to the class.
Merge pull request #205 from IQAndreas/organize-flixel

Organize Flixel into packages

Fixes #194

* Change main package from `org.flixel` to just `flixel`
* Organize Flixel's classes into several, more logically organized packages
* Rename `FlxAnim` to `FlxAnimation`
Add `FlxRandom` class

Basic framework set up; more to come!
Add basic methods to 'FlxRandom'

Also added a slight notice at the top crediting the sources for most of
the code.
Add more features to 'FlxRandom'

Also added more arguments to some of the existing functions.

I think I'm almost satisfied with this class now.
Improve `FlxRandom` ASDoc

Plus some slight bug fixing (also removed two "untyped" warnings that I
missed). Pretty good turnout for a class I didn't test before
committing.
Deprecate old methods involving randomness

I didn't delete them, just moved them "out of the way" and added a
`@deprecated` flag, as well as a warning every time someone tries to
access them (see `FlxG.warnDeprecated()`).
Update existing references to deprecated methods to point to new members

Also did some performance tweaking, and in some cases, cut out large
chunks simply for the sake of clarity, nothing more.
Fix ASDoc for FlxRandom

Apparently, you can't have anything after the @see (or any other
@something) variables.

Second, the ASDoc compiler doesn't like the less than or greater than
symbols.
Merge pull request #207 from IQAndreas/flx-random

Add 'FlxRandom' pseudo-random number generator
Make 'utils' executable

They weren't due to me previously having stored the entire project on an external NTFS harddrive,
which obviously didn't support Linux's permissions system, but instead treated every file as
having 755 permissions.

It is fixed now. :)
Update 'generate-asdoc' to allow for a 'lib' folder

Realized this was required when I tried to generate the documentation
for [Flixel Power Tools](https://github.com/FlixelCommunity/Flixel-
Power-Tools/).
Fix `utils`

Changed permissions to 755
The `generate-asdoc.sh` script now allows for a `lib` folder.
Move some `FlxU` methods to `FlxPoint`

FlxU.rotatePoint() -> FlxPoint.rotate()
FlxU.getAngle()    -> FlxPoint.angleBetwee()
FlxU.getDistance() -> FlxPoint.distance()
Move some `FlxU` methods to `FlxMath`

`FlxMath` is a new Math class which is not dependent on any target
platform.

FlxU.abs()   -> FlxMath.abs()
FlxU.floor() -> FlxMath.floor()
FlxU.ceil()  -> FlxMath.ceil()
FlxU.round() -> FlxMath.round()
FlxU.min()   -> FlxMath.min()
FlxU.max()   -> FlxMath.max()
FlxU.bound() -> FlxMath.clamp()