project detection is done in multiple places, refactor needed

[jquelin]

look at r10100 the number of places where i had to change the way project detection is done. and that's not counting other places that i've already fixed.

==> padre::project::perl needs to be refactored to have subclasses such as: ppp::eumm, ppp::mb and ppp::dzil.

also, a ppp::eumm::mi subclass would be in order to.

- padre:project:perl would keep method detection, etc.
- subclasses would get:

. a detection method to know whether a given directory fits their model
. some run methods to know how to invoke build, test, etc.

etc.