Added ebuild for eclipse's reference implementation of JPA 2.1

Package-Manager: portage-2.2.7
Added virtuals for JPA

Package-Manager: portage-2.2.7
Fixed dependency

Package-Manager: portage-2.2.7
Added ebuild for log4j:2

Package-Manager: portage-2.2.7
Merge pull request #18 from ercpe/log4j-2

Ebuild for dev-java/log4j:2 and dependencies