Debugger/CDB: Windows 64 integer handling.

Convert CDB unsigned integer values should they appear in hex,
make format flexible.
Use int64 for reformatting integers to be able to accommodate
64 bit values on Windows 64. Add some more integer types.
Do not save decimal type formats. Add menu option to clear
individual formatting. Do not use map[] to query the type formats
(inserting 0 everywhere as a side effect).

Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@nokia.com>