Merge pull request #4 from dave-tucker/master

Add PCRE support for nginx
[pcre] Show correct logging messages
[nginx] Print message when installing
[nginx] Ensure $BUILD_DIR/local exists before installing
[README] Use bash code block syntax
[nginx] Re-enable PELICAN_SITEURL redirecting

Now we have pcre installed we can add this back
Update nginx and pcre
[pcre] Fix typo in installation message
Move launch-nginx from sbin to bin
Ensure /app/local/sbin is created
Disable cache

Every time I deploy my website, something breaks
with the existing cache, disabling until time to
investigate this properly.
Re-enable Cache