Merge branch 'release/0.7.8' into develop
Make login and show member work with ZF2
Make members list, pagination and simple search work with ZF2
Get list now returns an array
ZF2:core Db object improvments / members

Core DB
- execute() a query, will log as debug query string, and log errors
- add a delete($table) method that will automatically add database prefix
- return connection (mainly for transaction)

Members removal is now working

Refactor existing migrate code to reflect latest changes in core Db.
Make member modification work, add some wrapper method to Db

Change existing ZF2 code to use wrappers, make some WHERE clauses to work (silent fails)
Display member contributions
Bump version, set compat version as 0.8
Fix filtering on up to date members
Members getList no longer retruen an array, just use toArray when needed
Edit groups
Contributions list
Transactions list
Attach existing contribution to transaction
History and MailingHistory
CSV imports and exports
Charts
Align comments, cleanup
Picture insertion and deletion
Preferences insertion and deletion