old-configure and js/src/old-configure interestingly didn't handle both
the same way. But vtune support is only actually implemented in js/src,
so only the rules from js/src/old-configure matter (nothing was
enforcing the decistion from old-configure to js/src/old-configure), and
this is what is implemented here.
Note the AC_DEFINE used to be in a COMPILE_ENVIRONMENT block, but the
define is actually used in Gecko preferences, so it's actually better
that the define is always set when MOZ_APPLEMEDIA is enabled.
The implementation is a bit circumvoluted, but we do need to share
options between the top-level and js/src configures, possibly with
different defaults, and to properly pass things down from one to
the other. Until we are further down the road and can actually merge
both configures, this is a necessary evil.
Because --enable-application is the current way to do things, transpose
it to configure.py, but since --enable-application=js doesn't make
sense, make it an alias of a new --enable-project option.
This only partially moves --enable-application out of old-configure.in
because there are a lot of other things intertwined with it.
