[NaCl SDK] genhttpfs.py: allow filenames with spaces in them.

[NaCl SDK] genhttpfs.py: allow filenames with spaces in them.

Allow special characters such as spaces in filenames.

Also includes some general cleanup, and documentation.

Committed: https://crrev.com/f024036686219f4714c0f30dbb9dc7d5ef456333
Cr-Commit-Position: refs/heads/master@{#292713}

[Sam Clegg, 2014-08-29 16:53:22]

sbc@chromium.org changed reviewers:
+ binji@chromium.org

[binji, 2014-08-29 22:01:12]

lgtm

[Sam Clegg, 2014-08-29 22:11:08]

The CQ bit was checked by sbc@chromium.org

[commit-bot: I haz the power, 2014-08-29 22:21:05]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/sbc@chromium.org/15854004/2001

[commit-bot: I haz the power, 2014-08-29 23:21:26]

Committed patchset #2 (id:2001) as b7932896faab226dd46b16cdc5a97d37ecb89657

[commit-bot: I haz the power, 2014-09-10 03:11:36]

Patchset 2 (id:??) landed as
https://crrev.com/f024036686219f4714c0f30dbb9dc7d5ef456333
Cr-Commit-Position: refs/heads/master@{#292713}