Fix build problems

@Dylnuge @cyril-sf 

See commit messages. Cyril helped with the first commit (ember-template-compiler), Dylan will care about the second commit.
Hmm, that doesn't seem to work for some reason. Npm install complains: `The package ember-template-compiler does not satisfy its siblings' peerDependencies requirements! Peer grunt-ember-templates@0.4.21 wants ember-template-compiler@>=1 <2`. I'm confused by this, so I'll wait to see if your PR goes through in grunt-ember-templates.