Fix file permissions.

* Set the execute bit for python frontend.
* Unset unnecessary execute bit for other files.

Then we can run goagent with `./proxy.py` for short (compared to `python
proxy.py`.
Merge pull request #65 from pallxk/3.0

Fix file permissions.
Merge remote-tracking branch 'refs/remotes/goagent/3.0'
improve dnsproxy
bugfix for adsl support
Merge remote-tracking branch 'refs/remotes/goagent/3.0'

Conflicts:
	local/goagent.exe
certificate bugfix for chrome 39+
bugfix for CPU 100% usage for linux/macosx
adsl support for win8
hide pagespeed
bump version to 3.2.3
Merge remote-tracking branch 'refs/remotes/goagent/3.0'

Conflicts:
	README.md
	local/goagent.exe