Windows: Fix compiler warnings due to type mismatches

Windows: Fix compiler warnings due to type mismatches

There are some differences in how the DWORD type is defined between
native Windwos compilers and Cygwin where the former always uses long
and the latter uses long or int depending on the architecture. Since
the DWORD type is always 4 bytes, all uses of DWORD in printf are
cast to unsigned int, which consistently 4 bytes across all platforms.
Other mismatching printf format specifiers were also changed appropriately.

Additionally, a type cast is added for _beginthreadex on Cygwin.

Closes #106

Signed-off-by: Chris Dickens <christopher.a.dickens@gmail.com>