Update hyperlinks Use https whenever possible, and replace some outdated links.
win32_*.c: avoid some format string warnings These aren't real issues as all the types in question are 32-bit ints, but fixing these will prevent warnings later if we're ever able to enable __attribute__((format)) on Windows (hopefully due to https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64862 being fixed).
Update some copyright years
Consistently use _WIN32 instead of __WIN32__ _WIN32 works with all compilers, while __WIN32__ is MinGW-specific. This project used __WIN32__ in files that only support MinGW, and _WIN32 in other files such as the library header and example programs. One place even used WIN32. Avoid this unnecessary complication by just always using _WIN32.
Use native Windows threads on Windows This makes building wimlib for Windows easier, as it no longer depends on winpthreads.
Remove support for Windows XP
Mark VSS support non-experimental
vss: support on Windows XP
vss: note that it's only supported on Vista and later
vss: add useful warning for WOW64 processes
Add experimental support for Windows VSS