translation between field & piece directions.

* minor refactoring within FieldDirection.java
* better comments in Motion.java
put the unblockable variable into a movepattern.

thus only full movement patterns are jumps/unblockable, not a few single unblockable motions within a movement pattern. it made no sense.
Merge branch 'develop' of github.com:NPTricky/ccd-colon-colon into develop.movement_system
convenient string within the player enum.

might be used as an easy way to name a player.
valid movement system as good as complete.

cleaned up some imports.
getWhetherCrossingCenter now in use
fixed some logical issues
added support to unblockable motion patterns
minor refactoring - style issues
fixed and optimized ValidMovementSystem.java

* fixed some statement branching
* optimized statements
* refactored unblockable to the more self explanatory "isJump"
found another boolean optimization
fixed logical error

a jumper was able to capture pieces before the end of its movement pattern
fixed wrong use of short-curcuit AND
mask is now saved for each motion pattern

* some beautification of the valid movement system
* movement doesnt save a mask anymore
* motion pattern provides further constructors and piece creation refactored accordingly
shortened unnecessary methods of VMS
cut the recursive method down to 150 lines
major cleanup in the paint system & factory

thus the chessboard is currently drawn at a wrong position, but this isnt critical at all and doesnt affect anything else.
cleanup of the piece factory in the spirit of...

clean code development!
Merge branch 'develop' into develop.movement_system
debugged the valid motion system

with the help of "getWhetherCrossedCenter" it was possible to test the system for the first time