MakeMaker-generated Makefile.PL now only has configure_requires of
6.30 so dists can be installed on RHEL5
improve consistency and options of *_TESTING env vars (Apocalypse)
improve FileFinder-related documentation (thanks, Apocalypse)
add a default file finder called :IncModules (thanks, Apocalypse)
add a default file finder called :MainModule (thanks, Mateu X.
Hunter)
phase for named Prereqs defaults to Runtime if omitted (Jonathan Yu)
extract the *Runner role implementations from ModuleBuild to
Role::BuildPL (Leon Timmermans)