Simplify the people creation API a lot; now we have only IPersonSet.createPersonAndEmail() which will do everything that's needed. r=jamesh
Patches applied:

 * guilherme.salgado@canonical.com/launchpad--smallfixes--4--patch-9
   Get the new bounty subscription page working.

 * guilherme.salgado@canonical.com/launchpad--smallfixes--4--patch-10
   Duh! last commit was empty. It was supposed to be issued in another tree.

 * guilherme.salgado@canonical.com/launchpad--smallfixes--4--patch-11
   Simplify the people creation API.

 * guilherme.salgado@canonical.com/launchpad--smallfixes--4--patch-12
   merge from rf

 * guilherme.salgado@canonical.com/launchpad--smallfixes--4--patch-13
   merge from rf

 * guilherme.salgado@canonical.com/launchpad--smallfixes--4--patch-14
   Removing unused imports

 * guilherme.salgado@canonical.com/launchpad--smallfixes--4--patch-15
   merge from rf

 * guilherme.salgado@canonical.com/launchpad--smallfixes--4--patch-16
   Remove unused imports from gina/handlers.py and the duplicated IPersonSet.createPerson()

 * guilherme.salgado@canonical.com/launchpad--smallfixes--4--patch-17
   merge from rf