test: fix matrix-test on big endian systems
RELEASING: Add note about changing the topic of the #cairo IRC channel
test/scaling-bench.c: New benchmark for bilinear scaling

This new benchmark scales a 320 x 240 test a8r8g8b8 image by all
ratios from 0.1, 0.2, ... up to 10.0 and reports the time it to took
to do each of the scaling operations, and the time spent per
destination pixel.

The times reported for the scaling operations are given in
milliseconds, the times-per-pixel are in nanoseconds.

V2: Format output better
Add support for iter finalizers

Iterators may sometimes need to allocate auxillary memory. In order to
be able to free this memory, optional iterator finalizers are
required.
Add an iterator that can fetch bilinearly scaled images

This new iterator works in a separable way; that is, for a destination
scaline, it scales the two involved source scanlines and then caches
them so that they can be reused for the next destination scanlines.

There are two versions of the code, one that uses 64 bit arithmetic,
and one that uses 32 bit arithmetic only. The latter version is
used on 32 bit systems, where it is expected to be faster.

This scheme saves a substantial amount of arithmetic for larger
scalings; the per-pixel times for various configurations as reported
by scaling-bench are graphed here:

	http://people.freedesktop.org/~sandmann/separable.v2/v2.png

The "sse2" graph is current default on x86, "mmx" is with sse2
disabled, "old c" is with sse2 and mmx disabled. The "new 32" and "new
64" graphs show times for the new code. As the graphs show, the 64 bit
version of the new code beats the "old c" for all scaling ratios.

The data was taken on a Sandy Bridge Core i3-2350M CPU @ 2.0 GHz
running in 64 bit mode.

The data used to generate the graph is available in this directory:

    http://people.freedesktop.org/~sandmann/separable.v2/

There is also a Gnumeric spreadsheet v2.gnumeric containing the
per-pixel values and the graph.

V2:
- Add error message in the OOM/bad matrix case
- Save some shifts by storing the cached scanlines in AGBR order
- Special cased version that uses 32 bit arithmetic when sizeof(long) <= 4
Merge branch 'master' of git://anongit.freedesktop.org/git/pixman