Disable automatic detection of devel/boost-libs if installed. This prevents
unnecessary linking to libboost_atomic.so if installed on FreeBSD 10.x and
use of the boost headers elsewhere.

Bump PORTREVISION to rectify stray linking if taglib was built outside of a
clean environment.

While here, switch to CMAKE_ARGS to CMAKE_ON and switch RCC_[CFLAGS|LDFLAGS]
to RCC_USES=localbase:ldflags

Reported by: Tatsuki Makino <tatsuki_makino@hotmail.com> (via private mail)