Missing bits for evernote/pootle@2d175ba0

These are missing bits that were not picked previously.
Missing bit from pick of evernote/pootle@17a646b8
Move top progressbar to the header

Conflicts:
	pootle/templates/translation_projects/overview.html
Move 'expand/collapse details' section to the header

Conflicts:
	pootle/static/css/style.css
	pootle/templates/translation_projects/overview.html
Adjust styling
Partial pick: Remove units from stats calculation an template

(The number of units is not important given that we display the number of words, which is more accurate)

Pick note: Most of the remaining changes are not necessary since we picked
    later commits that rendered these changes useless. I am not sure about
    some of the other changes, but if they are necessary they can be easily
    picked in the future.

Conflicts:
	pootle/apps/pootle_misc/checks.py
	pootle/apps/pootle_misc/stats.py
Remove unused imports (as kindly reported by PyCharm)

Pick notes: The rest of the changes were not necessary.

Conflicts:
	pootle/apps/pootle_app/models/directory.py
Not show progressbar for parent folder

Conflicts:
	pootle/templates/core/table.html