Merged from trunk -r13703:13717

   Merged from trunk -r13703:13717

   | 13716   | Bug #270953 - New !!atom blockers do not allow temporary     |
   | zmedico | simulaneous installation, so unlike !atom blockers, !!atom   |
   |         | blockers aren't ignored when they match other packages       |
   |         | occupying the same slot. Thanks to Sebastian Mingramm (few)  |
   |         | <s.mingramm@gmx.de> for the initial patch.                   |

   | 13717   | * Add new abstract PhaseCheck class for ebuild               |
   | zmedico | phase-specific checks. * Reimplement SrcUnpackPatches using  |
   |         | PhaseCheck. * Add new SrcCompileEconf,                       |
   |         | Eapi3IncompatibleFuncs, and Eapi3GoneVars checks. Thanks to  |
   |         | Markus Meier <maekke@gentoo.org> for this patch.             |

svn path=/main/branches/prefix/; revision=13721