BPackageInfo::Parser::_ParseFlags(): fix indentation
package info parser: improve string parsing

* Instead of two string token types (TOKEN_WORD, TOKEN_QUOTED_STRING),
  there's now only one (TOKEN_STRING). Whether the string meets the
  criteria is checked where needed. In most cases the check was already
  done or not necessary anyway.
* Strings can now consist of an arbitrary sequence of quoted and
  unquoted strings and escaping is also supported in unquoted string
  segments.
* Among other things this fixes incorrect restrictions for resolvable
  names and should also make quoting paths superfluous (unless they
  contain separator characters).