Revert changes that enabled usage of mp3 lame shared library. Due to revertion
of shared library build/installation on the lame port PORTVERSION=3.70,
PORTREVISION=2.
1) Add audio/lame as a LIB_DEPENDS 2) Have this port use the port's system
shared version of the lame library instead of building its own static version.
Add both some detection code and necessary hooks to avifile's configure system
(defensive programming) using some patches 3) Add a simple stale port's tree
defensive check. After the library dependency phase, if one gets a lame
library but no shared library ... bogus. The avifile depending on the new
version of lame port was added after the aforementioned. Warn the user about
it. A side effect (of LIB_DEPENDS) is that the new lame dependency is always
built even if there is an old version of lame installed. 4) PORTREVISION bump