Remove code that un-suffixes collect-ed keys

In order to handle dynamic "other" keys we need to remove what are effectively duplicate keys. The un-suffix-ed keys were only used in a few places.
Group data before calculating "other" and "total" fields

When applying group mapping, we need to do it before we calculate the "other" field because datasets might get grouped into defined groups.

Only include data groups without a defined line in total figures if there is also a defined line for "other", to ensure the numbers displayed to a user always add up to the total.

Support regular expressions for group mappings.
Implement browser version breakdowns for browser module

Split IE traffic into <=8 and 9+
Scale up grouped timeseries percentage graphs when all the percentages are small

To avoid getting everything scrunched up at the bottom of the graph.
Update module schemas to allow multiple group_by params
Add browser module to all site activity dashboards
Merge pull request #735 from alphagov/feature/browser-versions

Feature/browser versions