Add listAddressbook to api

listAddressbook returns label and address for each address in the
addressbook.
Move duplicated sql code into helper
Have API calls use sql helper
Have bitmessageqt use sql helpers
Have helper_inbox use helper_sql
class_singleCleaner uses helper_sql
Merge branch 'master' into sql_refactor
use helper_sql for helper_sent
use helper_sql in class_singleWorker
use helper_sql in class_receiveDataThread
have shared.py use helper_sql and move the sql queues and locks to helper_sql
Merge branch 'master' into sql_refactor
new API method needs to use helper_sql
Fix regression where I couldn't add a subscription
Fixed regression in adding to address book
Merge remote-tracking branch 'upstream/master' into sql_refactor
Added SqlBulkExecute class so we can update inventory without a million commits
fix #464
Merge pull request #466 from Atheros1/master

fix #464
Merge branch 'sql_refactor' of git://github.com/grant-olson/PyBitmessage into grant-olson-sql_refactor