Fix the erubis auto escape faq bit.
* Cleaner Rakefile

* Instead of "file" task for the _sinatra and _contrib directories,
* this now uses "directory" task which removes the needless checking if
* there is a directory named _sinatra/_contrib

* The default rake task also depends on "_contrib" task or else latest
* changes in contrib directories are not updated in the website

* Cleaned up CLEAN and CLOBBER directives by moving all individual
* calls into single calls
Regen prebuilt files