From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

We add stripes for different stages of request execution so it is easier
to follow one context in the multi-colour mode.

Vertical stripe pattern indicates pipeline "blockages" - requests waiting
for dependencies before they are runnable.

Diagonal stripes indicate runnable requests waiting for GPU time.

Horizontal strips are requests executing on the GPU.

Also use this new multi-coloured mode from media-bench.pl.

v2:
 John Harrison:
 * Mention media-bench.pl in the commit.
 * Fix HTML for single colour mode.

v3:
 * Rebase.
 * Apply stripes to legacy colouring as well.

v4:
 John Harrison:
 * Use per context colours for ctxsave and incomplete boxes.
 * Clearer timeline legend.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>

Reviewed-by: John Harrison <John.C.Harrison@Intel.com>