Webkit libstc++ for clang.
Update Python version to 2.7.6., use https.
Add boehm-gc (garbage collection) for guile2.

Mind, guile2 still won't build, but that's another issue.
Fix libffi autogen template to something that works.
Patch wrong include order in old versions of gstreamer's gstdatetime.c

Swapping the positions of includes for glib-compat-private.h and
gst_private.h prevents getting the following error while building:

 error: use of undeclared identifier 'g_log_domain_gstreamer'

Note: This has been fixed upstream in gstreamer 1.2.1
Fix configure and compilation errors when building liboil

Use AC_CONFIG_HEADERS macro (instead of AM_CONFIG_HEADER) to allow
configuring, and add -fheinous-gnu-extensions to CFLAGS to avoid
getting a compilation error in amd64/wavelet.c when using Xcode 5.