Prepare configuration parsing code to be called multiple times:

Prepare configuration parsing code to be called multiple times:
- Don't exit on errors if not requested.
- Don't keep configuration in global variable, but allocate memory for
  configuration.
- Call yyrestart() before yyparse() so that on error in configuration file
  we will start from the begining next time and not from the place we left of.

MFC after:	1 month