[physfs] lzma.c msvc, etc. patch

[Ryan C. Gordon]

> Isn't casting a void pointer to an unsigned long going to create 64-bit 
> portability problems? From what I understand, even on 64-bit x86 CPUs a 
> long is only 32 bits wide, whereas a void pointer will be 64 bits. If 
> true, there'll be data loss casting a void pointer to an unsigned long.

It'll work on Linux/amd64 ("long" is 64 bits in gcc), but not Win64 
(long is still 32 in vc++).

We don't have a PHYSFS_ptrint type at the moment. We should, though.

--ryan.