Lexer:
- proper support of preprocessor
- parse float numbers
- octal&hex escape sequences
- wide string constants
- proper handling of different file encodings

Parser:
- the expect macros abort functions directly. This leads to some functions
  not resetting the current context properly (parse_for)
- proper handling of function pointer types
- outermost typequalifiers can differ between function declarations and
  implementations...
- fix semantic to ignore type qualifiers (const double is the same as double)
- label: declaration; is no valid C99 but we parse it anyway

ast2firm:
- output source file positions for panics...
- correctly handle pointer ++, --


Coole Warnungen:

	int x = 5;
	x = bla():

	-> dead assignment