Before this patch, every request in development caused the template
to be compiled, regardless if it was updated in the filesystem or not.
This patch now checks the timestamp and only compiles it again if
any change was done.
While this probably won't show any difference for current setups,
but it will be useful for asset template handlers (like SASS), as
compiling their templates is slower than ERb, Haml, etc.
Guillermo Iguaran