Adapted secaudit and usermap (now ntfssecaudit and ntfsusermap) to ntfsprogs

Adapted secaudit and usermap (now ntfssecaudit and ntfsusermap) to ntfsprogs

These tools were originally developed for running on Windows and later
ported to libntfs-3g. This patch makes them similar to other ntfsprogs
tools, dropping the native Windows interfaces and using libntfs-3g on
all platforms.

There is no change in usage or supported features, only the command
names have changed.