msvcrt[1/5]: fill _mbctype table in _setmbcp

[Mikolaj Zalewski]

These patches are supposed to give some solid foundations to implement
_mbsbtype. The first one fill the _mbctype table with information that
will be used by functions depending on mbcp. The trail bytes data
seems to be unavailable so I added it in msvcrt for DBCS codepages we
support.

There are two wine_todo but they are caused by wrong data returned by
kernel32 - the native msvcrt on Wine gives the same failures (one that
could be important is that on Windows char 143 is not a lead byte in
codepage 20932).