very basic changes from [PreLexNode] to [[PreLexNode]] for recursive
usage
Merge branch 'preproc-lexer' of https://github.com/SWP-Ubau-SoSe2014-Haskell/SWPSoSe14 into preproc-lexer

Conflicts:
	src/RailCompiler/Lexer.hs
made follower id easier to merge and satisfy hlint
made a merging function as preparation for junctions
restructuring of merge function
junction attempt
simple junction tests working
exported new helper function for usage in editor
forcing x+* junctions to move forward
more lexer tests
merge function fixed to satisfy new tests
more lexer test cases (that actually made me discover bugs to fix)
fixed push/pop bug and added test case
small fix in junction processing
Lexer changes:

- Added NOP to lexemes.
- Added export for lambdadirs.
Merge branch 'preproc-lexer'