Templates: reflow
Various: pull from Pootle
Exclude alt-src languages

- We can now define alt_src languages for a project
- These will not be used in default actions for tools
  e.g. ttk-get will only retrieve non-alt-src langs
Allow --keep type behaviour

If you issue ttk-put --keep=NNNN then we enable --keep and
--modified-since=NNNN behaviour.