Add last-activity snippet
Use mtime as timestamp instead of isoformat to get a last action
Set default empty value for get_last_action method, add get_parent function
Delete getquickstats
FOLLOWUP: Adapt our code
FOLLOWUP: More code adaptation

As a side effect we no longer try to generate stats immediately after
updating against templates or from VCS, as I think this should speed
those operations considerably and we generate the stats on the fly later
when needed.
Use new stats in get_translation_stats function
Adapt more code to new stats
Calculate and fill in the completeness ratio used for sorting
Update spin.js to the newest version (1.3.2) + adjust its defaults
Show spinner until stats are loaded
Show spinner early when requesting extended stats; show it on <body> tag
Until stats are loaded, show semitransparent graphs
Cleanup: PEP8 and coding style fixes
Not use get_raw_stats for Store
Delete get_raw_stats function
FOLLWUP: Adapt our code
Add qualitychecks and translation stast ajax rendering (getting data via treeitem interface)
Add translation actions ajax rendering, add critical column to main table view
Test if check has defined name