processing includes as proposed in #67

[Idrinth]

This processes includes (and include-likes, like require_once) in the AST of files defined by any loading mechanism and processes all files that may reasonably be matched by the given include-like.

This is not feature complete and lacks tests, consider it a WIP, that I'd like feedback on from @Ocramius and @simara-svatopluk .

[Idrinth]

if these changes are ok, I'll squash them @Ocramius

[keradus]

btw, squash can be done automatically during merging ;)

[Idrinth]

sure, just depends on how the project is setup, @keradus :) somehow few people seem to use the automatic one