the inital work for this commit was coming from `Mark van der Putten`.
In order to not have more options for this, the idea came up to use
mesons autodetection using PATH.
If a cross file is specified, the binaries are used from the system,
rather than from the intree. (Which means --cross-file has the
dependency of efl on the buildsystem)
Differential Revision: https://phab.enlightenment.org/D7415