Display last update time and date in footer

See issue #323
Merge pull request #324 from flodolo/last_update

Display last update time and date in footer
POC repos & components status
Grep keys then build arrays
Better results, remove special cases
save
Initial UI
Get locales_list right
Move functions to a new class, get stats
Add Health tests
Display basic info
save
fix style a bit, remove extra rows
fix en-US
Add missing tests
Fix error when extracting stats
Add VersionControl tests
Code cleanup + improve global completion status