Script to load polling centers. Also renamed PS to PX to avoid confusion
b/w polling station and booth.
fixed references to PS.

It has been renamed as PX.
Added ability to edit PB/PX mapping if there are any errors.

This can be done from ACxxx/booths page

Conflicts:
	voternet/models.py
Improved the UI on the place page.

Changes:
* Removed coverage, not relevant close to elections.
* grouped buttons into a row
* Removed info tab.
added counts and progress bar for booth and center agents.
ui tweaks
added color to progress text
fixes
auto assign ward to PX
fix
another fix
consider every polling center with at least one booth agent or center agent as covered.
typo
show polling center agents
tweaks
include px_agent and pb_agents in download-volunteers
fixed bag grouping in a px counts query.
px listing of AC
include px name
include ac-name as well.