Add support for creating hidden ramdisks (not visible in the Finder sidebar)
Fix warnings

Switch to u_int64_t for ramdisk size everywhere. Removes the cast to
u_int32_t from int64_t that caused one of the warnings.
Fix warnings (continued)
Small improvement

Slightly shorter/better version of the command used to create
and mount a hidden ramdisk. Still looking for an even better
alternative though.
Removes advanced binding from hidden button.