Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Fix whitespace inconsistencies found in homegrown Symbol.maps.

Rename all symbols in libmp(3) to mp_*, just like Solaris.

The function pow() in libmp(3) clashes with pow(3) in libm. We could
rename this single function, but we can just take the same approach as
the Solaris folks did, which is to prefix all function names with mp_.

libmp(3) isn't really popular nowadays. I suspect not a single
application in ports depends on it. There's still a chance, so I've
increased the SHLIB_MAJOR and __FreeBSD_version.

Reviewed by: deischen, rdivacky