Reorg and cleanup, add readme & docs on third party additions

BUG=skia:5602
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2302913002

Committed: https://skia.googlesource.com/skia/+/005327b9ddbf0bb2890c7d563b3d9a8ea8a284f6

[hcm, 2016-09-01 14:23:48]

Description was changed from

==========
fix files uploaded

BUG=skia:
==========

to

==========
fix files uploaded

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2302913002
==========

[hcm, 2016-09-02 14:23:08]

Description was changed from

==========
fix files uploaded

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2302913002
==========

to

==========
BUG=skia:5602
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2302913002
==========

[hcm, 2016-09-02 14:23:08]

hcm@google.com changed reviewers:
+ rmistry@google.com

[hcm, 2016-09-02 14:26:01]

On 2016/09/02 14:23:08, hcm wrote:
> mailto:hcm@google.com changed reviewers:
> + mailto:rmistry@google.com

Just getting these top level files adjusted/in place.  Will handle lower level
directories on case-by-case as added/modified.

[rmistry, 2016-09-02 14:28:14]

lgtm

[hcm, 2016-09-02 14:30:18]

The CQ bit was checked by hcm@google.com

[commit-bot: I haz the power, 2016-09-02 14:30:22]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-09-02 18:19:45]

Description was changed from

==========
BUG=skia:5602
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2302913002
==========

to

==========
BUG=skia:5602
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2302913002

Committed:
https://skia.googlesource.com/skia/+/005327b9ddbf0bb2890c7d563b3d9a8ea8a284f6
==========

[commit-bot: I haz the power, 2016-09-02 18:19:46]

Committed patchset #3 (id:40001) as
https://skia.googlesource.com/skia/+/005327b9ddbf0bb2890c7d563b3d9a8ea8a284f6