Integration with PyG3t
Pyg3t is a toolkit that helps translators to perform some tasks with PO files. For the most useful are gtxml (to check documentation files for XML typos) and poselect to filter PO files by number of untranslated/fuzzy strings.
These could be implemented as GTR plugins to add more features, but gtxml should be a core check to avoid problems with documentation files (similar to msgfmt)