Update the git location to be current, rename all instances of Play20 to playframework,
update more docs where Play20 should be replaced with playframework
Point CONTRIBUTING.md to make new issues in Github rather than lighthouse
Merge remote-tracking branch 'upstream/master' into patch-2

Conflicts:
	README.md
Merge pull request #1354 from wsargent/patch-2

Change the Play20 name to playframework at github