Replace a repeated method call with one variable

Change-Id: Ifd848249034e65348b18087b66c3a7245f144710
Save source and target language in change tag parameters

Change the cxpublish API to accept source and target languages.

Change-Id: I8ccabb8cf0d887518c5e21303795cc2431725e40
Merge "Replace a repeated method call with one variable"
Merge "Save source and target language in change tag parameters"