update some comments and newToken(). disable old function perm(). remove
old stuff.
first impl. of genWaveHeader()
disable function readWaveHeader() (moved to class Wave)
insert readWaveHeader from class database.
init. attr. user_perm as an empty array.
fixed: https://github.com/TGM-Oldenburg/AccessDB/issues/49 ,
recoverWave() check wave for valid header.
fixed: https://github.com/TGM-Oldenburg/AccessDB/issues/49
fixed: https://github.com/TGM-Oldenburg/AccessDB/issues/49