arb_texture_multisample: add test for sampling from depth

This demonstrates an i965 bug, where hiz resolves for MSAA surfaces
don't work (on BLORP platforms).

Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>
Reviewed-by: Glenn Kennard <glenn.kennard@gmail.com>
all.py: Replace testsDir and generatedTestDir with PEP8 variables

testsDir -> TEST_DIR
generatedTestDir -> GENERATED_TEST_DIR

Signed-off-by: Dylan Baker <dylanx.c.baker@intel.com>
all.py: Move all helpers to the top of the module

Signed-off-by: Dylan Baker <dylanx.c.baker@intel.com>
wip: all.py: make group names lower case
squash! wip: all.py: make group names lower case

Update results version to v3. This fixes the groups are all lowercase.
all.py: Remove explicit additions of -fbo and -auto

commit c6fc8b36 caused the PiglitGLTest class (which is the primary test
class used in all.py) to automatically add -auto and -fbo when it is
appropriate. This means by having these we're storing data that doesn't
need to be stored.

Signed-off-by: Dylan Baker <dylanx.c.baker@intel.com>