Add county id to reports/ allow group by on reports (by county id & custom fields)

We have a requirement from a customer to be able to run a bunch of reports with the option to group by on custom fields & on county. I tried on pledge summary report & found it not too difficult - patch attached.

I'd like to do this over a handful of reports - ie. pledge detail, book-keeping, activity & survey detail so would be good to get quick feedback if there are any issues.

A few notes:

1) If the clause generated by buildACLClause is being used anywhere I couldn't see it
2) I'd like to make it so they can choose not to display contact_name (e.g. when aggregating all records by county). I couldn't figure out how
3) it seems to me that maybe we should create a function like below to call from the various construct functions to make them more consistent.

If you are happy with all this please assign back to me & I can commit this & ammend & commit the others.

CRM_Report_Form::addAddressFields()

{ return array( 'civicrm_address' => array( 'dao' => 'CRM_Core_DAO_Address', 'fields' => array( 'street_address' => null, 'city' => null, 'postal_code' => null, 'state_province_id' => array( 'title' => ts( 'State/Province' ), ), 'country_id' => array( 'title' => ts( 'Country' ), 'default' => true ), 'county_id' => array( 'title' => ts( 'County' ), 'default' => false ), ), 'group_bys' => array( 'street_address' => null, 'city' => null, 'postal_code' => null, 'state_province_id' => array( 'title' => ts( 'State/Province' ), ), 'country_id' => array( 'title' => ts( 'Country' ), ), 'county_id' => array( 'title' => ts( 'County' ), ), ), 'grouping'=> 'contact-fields', ), }