rhbz730192 use localizable string (prev and next page controls on document list)
rhbz870876 allow download of po zip for offline translation for non-po projects in editor document list
clean up whitespace
refactor history token parsing
add message filter support in history
refactor TransFilterPresenter and display to add message filter history support
Merge branch 'integration/master' into rhbz846314
fix test, implement caching for target validation