includes: Add crt/long.bi to define CLONG and CULONG types

Since 64bit FB's data types don't exactly match the C types anymore,
it's nice to have some typedefs that declare types which match the C ones,
for use by C library bindings, for example.

FB's LONG is always 32bit like C's int, so that's no problem (besides being
a bit confusing).

FB's INTEGER however is 32bit or 64bit, and in general in C there's no
counterpart. On Linux/BSD C's long is also 32bit or 64bit, but on Windows,
C's long is always 32bit. Because of this INTEGER isn't a reliable
cross-platform translation of C's long.

The new crt/long.bi header is supposed to help out by providing reliable
CLONG/CULONG types that can be inserted where C's long is needed,
specifically in headers for C libraries.

It seems to be good to add these typedefs in a new crt/ header, so they're
available to any other binding without need for copy/pasting, and not
making them built-in types avoids creating new global keywords. Lots of
C libraries don't even use C's long, because it's unreliable like that,
and FB bindings for such libraries wouldn't need the CLONG/CULONG types.

http://www.freebasic.net/forum/viewtopic.php?p=186794#p186794
crt/ctype.bi: Fix isascii() and toascii() declarations
crt/bits/pthreadtypes.bi: Fix long int -> LONGINT confusion

The original pthreadtypes.h header uses C's long int type in many places,
(assuming a 32bit system) it must be translated as 32bit type (Integer or
Long), but definitely not FB's 64bit LongInt.

Note: The original pthreadtypes.h uses C's long long int type in some
places too, that is 64bit and needs to be translated as LongInt, so care
must be taken because this is extremely confusing either way.
crt/win32/process.bi: Fix spawnvpe()'s last parameter type
includes: Adjust CRT headers for 64bit
win/winbase.bi: Fix RtlFillMemory() & co declarations (fixes #434)