[CONUTILS] Diverse improvements: start doxygenating and add some resource messsage...

[CONUTILS] Diverse improvements: start doxygenating and add some resource messsage helper functions.

- Start to doxygenate the library, focusing in great details on the
  functions of the "outstream" module.
- Add a K32LoadStringEx function that expands (K32)LoadString by
  allowing a LanguageId parameter to be able to load strings from other
  languages than the current one.
- Add "ConResMsg*" helper functions to be able to (format and) print
  message strings with inserts that come *NOT* from a message table (as
  usual) *BUT* from resource string tables.
  Will be helpful for CORE-14265 in particular.

[CMD] Fix the call to ConMsgPrintfV().