docs/libs/gstreamer-libs-sections.txt: API: addition: gst_adapter_take_buffer()

docs/libs/gstreamer-libs-sections.txt: API: addition: gst_adapter_take_buffer()

Original commit message from CVS:
* docs/libs/gstreamer-libs-sections.txt:
API: addition: gst_adapter_take_buffer()
* libs/gst/base/gstadapter.c: (gst_adapter_push),
(gst_adapter_peek), (gst_adapter_take), (gst_adapter_take_buffer),
(gst_adapter_available_fast):
* libs/gst/base/gstadapter.h:
Prepare for optimizing the hell out of this hugely inefficient
piece of code.
Added gst_adapter_take_buffer() so we can at least start thinking
about subbuffering and merging.
Added some comments.
* tests/check/Makefile.am:
* tests/check/libs/adapter.c: (GST_START_TEST),
(gst_adapter_suite), (main):
Added GstAdapter check.