bugfixen for the error recovery code
interpret \r escape sequence correctly in regexen
make start condition mapping available to the lexer writer

* add the start condition mapping to the debug information
* use the start condition mapping where the lexer writer
  manipulates the condition stack
remove the reference from symbols to the syntax

* this reference was not used any where
* why has it been there in the first place
restructure pyLRp as package

* split the parser generator to multiple files
* XXX: some new code was added in this process (PyBlob, rudimentary
  $name-style references (additionally to the $N style ones, some
  comments)
* XXX: this breaks the unittests, they have to be adapted to the
  new structure
* some further restructuring remains to be done