Allow site generation via mklive outside the master branch
Don't allow push to live if staging revision starts with 'test-'

Force the start of the revision on staging to match "live-", rather
than matching "live-" anywhere in the string.
Make gollum launch/kill scripts cleaner

This fixes 3 things:

1. launch_gollum displaying an empty pid in the "Launching gollum
   with pid ...." message.
2. kill_gollum returning before gollum had actually closed down.
3. launch_gollum fails gracefully if netstat is not installed,
   instead of hanging forever.
Add links to channel viewer to download pages
Merge pull request #54 from townxelliot/release-channel-link-911

Add links to channel viewer to download pages
Correctly detect test-live-* branches
Update push.sh script instructions

As we can now push to staging from a branch other than master,
update the instructions to explain that.
Merge pull request #49 from townxelliot/mklive-outside-master-xwalk904

Allow mklive outside master
Clean up indentation and remove commented-out code

This is preparatory to replacing the http client code.

Note that this changes the script's behaviour so that it no
longer shells out to the 'php' command: instead, we use a
client which doesn't need allow_url_fopen to be set to true
in the first place.
Make function to wrap URL-opening fopen() calls

This is preparatory to rewriting the code to open URLs using
something other than fopen.
Add an HttpClient class

This gives the benefit of being able to read the proxy.config
file in once, rather than for every request.
Handle missing proxy.config error properly
Switch to cURL instead of fopen
First pass at caching wiki page fetches
Add caching based on file mtime (5 minutes)
Provide an error message if directory is not writable
Ensure missing() is given a file name
Use print() instead of echo() for consistency
Write HTML files out for 'documentation' and 'contribute'

This is necessary for when the gfm.php script is being used
to generate the live static site.
Add note that cURL extension for PHP should be enabled