Reorder imports
Always set the R and L flags when running on GAE

If the remote host is not present, show an error at runtime. This
is better than the "flag R provided but not defined".

Updates #3.
Reorder imports
Fix order when building project templates from multiple dirs

Add them in this order: _common -> _appengine (if enabled) -> template

This way _appengine specific files take priority over the common
ones and the template files take priority over the rest.

Fixes #3.