Misc: Simplify includes and misc. cleanup

* fxload sample provenance
* No need for <sys/types.h> in samples as already in libusb.h
* Don't bother about sscanf_s in xusb
* Use HAVE_### and rely on config.h where possible
* Formal inclusion of <winsock.h> in libusb.h for WinCE and WDK
* Cleanup of Windows' config.h
* Avoid ENAMETOOLONG and ENOTEMPTY conflict between errno.h and winsock.h for WinCE
* Additional newlines & braces cleanup
WinCE: Post integration cleanup

* Update copyrights and switch to UTF-8 everywhere
* Add SleepEx() to missing.h, and move include to libusbi.h
* Remove ifdef for GetSystemTimeAsFileTime()