backends: refactor transform string parsing

Most of the backends do their own parsing of transform strings, so let's
put that all in the same place (compositor.c/h)

Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
gl-renderer: compress pixman bands to simplify geometry

Pixman uses y-x banded rectangles to represent regions.  We use these
y-x banded rectangles to generate triangle fans, resulting in more
geometry than strictly necessary to draw the screen.

This patch combines the bands to reduce geometry for complex scenes.

Acked-by: "Jasper St. Pierre" <jstpierre@mecheye.net>
Tested-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Makefile.am: Link weston_multi_resource against rt library

This fixes this build failure:

/usr/lib/gcc/x86_64-unknown-linux-gnu/4.7.3/../../../../x86_64-unknown-linux-gnu/bin/ld:
clients/weston_multi_resource-multi-resource.o: undefined reference to
symbol 'clock_gettime@@GLIBC_2.2.5'
/usr/lib/gcc/x86_64-unknown-linux-gnu/4.7.3/../../../../x86_64-unknown-linux-gnu/bin/ld:
note: 'clock_gettime@@GLIBC_2.2.5' is defined in DSO /lib64/librt.so.1
so try adding it to the linker command line
/lib64/librt.so.1: could not read symbols: Invalid operation
xwayland: fix fullscreening

set_fullscreen has been sending configure before changing the state
and xwayland windows added border to the fullscreen size.

This fixes the bug:
https://bugs.freedesktop.org/show_bug.cgi?id=83502

Signed-off-by: Marek Chalupa <mchqwerty@gmail.com>
Reviewed-by: Ryo Munakata <ryomnktml@gmail.com>
Tested-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
compositor: Add idle timeout option to weston.ini

Weston's idle timeout can already be set via the '-i' command-line
option, but this patch lets users specify it also via weston.ini.
Note that the command-line option takes precedence over the .ini,
should the option be set by both.

This patch also Updates weston.ini man page with idle-timeout bits

https://bugs.freedesktop.org/show_bug.cgi?id=83921

Signed-off-by: Frederic Plourde <frederic.plourde@collabora.co.uk>
Reviewed-by: Bryce Harrington <b.harrington@samsung.com>
man: explain idle-time=0 in weston.ini

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>