Add docs for cache control plugin
Add support for zip, tar archive skeletons

Code inspired from https://github.com/JoeGermuska's contributions to
Cactus, commits:

156e96404ede59fa818154a7e61fbfa7441f4716
b6fab5dffa0e2ab083d45d4d0d1a01d4c8089f60
Add support for ignore patterns

Re-introducing the change by Koen in
5bd5a8884c6a766cd6e20718e2ff9d07bb4c505e

I didn't implement ignore patterns at the deploy level since the files
can't make it to the build folder at all (we clean the build dir before
a build/deploy).
Reconciled robots.txt with protocol

Reconciled robots.txt with Robots Exclusion Protocol. Defaults now specify that all pages are available and sitemap resides at /sitemap.xml.

See http://www.robotstxt.org/robotstxt.html and http://support.google.com/webmasters/bin/answer.py?hl=en&answer=183669 for more details.
Fix weird applescript escaping issues
Conflicts:
	cactus/browser.py
Move compatibility to its own package
Implement the legacy context (PAGE_URL, etc.)

This is superseded by template tags with can take care of prettified
URLS, as well as fingerprinted statics, but we need to provide them for
backwards compatibility.

Also added warnings when they're used, as well as tests
Added {% current_page %} template tag
Added tests for template tags