Expose SSL to context processor

This enables the developer to selectively use the secure URL. Currently
the setting is site-wide and this is fine for images but Chrome expects
to get CSS from a secure URL if the page itself is served from one.
Expose URLs to static CloudFiles storage to templates

This context processor allows drop-in replacement of local static
files with a CloudFiles CDN storage. The SSL URL is also provided
as a context variable in case it is explicitly required. In case
some files are stored locally in the STATIC_URL, it can be accessed
through the LOCAL_STATIC_URL context variable.
fixed bug that doesnt work on all python versions on different OSes