Adds period_end_date and map_view_quota to Users

period_end_date: next billing cycle for this user
map_view_quota:  total amount of map views per month a given
                 user is allowed to make

This commits also allows to update those attributes using
the superadmin API
Handle errors when calculating table size

* Don't raise an error when trying to calculate the size of a table
  that doesn't exist on the database.
* Remove unused data from user decorator.
Have CDB_QueryTable error out on unexplainable statements
Do not let CDB_QueryTables error out on non-select queries
Handle CDB_QueryTables errors on SqlParser
nokia params updated
Backport ability for CSV loader to import the_geom / the_geom_webmercator in HEXEWKB
Merge branch '2.0'