Added p3 package.
+
remove .native suffix from installed binary
Changed executable name from p3gen.native to p3gen
Merge branch 'tr61-master' of https://github.com/mirage/opam-repository

Conflicts:
	packages/p3.0.0.3/files/p3.install

Merge avsm suggested change to executable name.
Merge pull request #716 from tr61/master

Added p3 package to opam-repository