- rewrite follow function according to http://www.sciencedirect.com/science/article/pii/S030439759700296X, which makes a bit clearer what is going on inside
 - rename some foos and update doxygen

 - Removal of libaregexptree/RegExpAlphabet
 - Method getting regexp alphabet moved to alib/RegExp, alib/RegExpElement
 - Method getting get symbols list in order moved to aconversion/GlushkovTraversal as Glushkov algorithm is the only one using it
 - Reflect changes throughout project

 - Fix StringPrinter
 - RemoveAlphabetSymbol() now checks for symbol presence in both alphabet and content.
 - some constness
 - Doxygen (original was obviously copy-pasted)

 - Note that this requires arand executable which is not finished yet, but obtainable from branch genRandAutomata.

 - RE to FA: comments
 - RE to RRG: fix generating epsilon rules and workaround for issue #22