GUIEpgGridContainer: split Render() into Process() / Render()
GUIEpgGridContainer: get rid of GetRulerCacheOffsets() method which is just duplicated GetProgrammeCacheOffsets()
GUIEpgGridContainer: get rid of unused now (and never should be used) m_renderTime
GUIEpgGridContainer: fix memory freeing for ruler items
GUIEpgGridContainer: fix memory freeing for programme items
GUIListItemLayout: SetWidth() / SetHeight() - mark invalid only when new size is different from old one
[musicdb] fix: unchecked access to albumartists/artists causes us to crash when they're empty
jsonrpc: fix return value of "volume" property in Application.GetProperties
settings: fix resolution changed popup on fresh installs
changed: show debug settings at standard level
changed: improve logging customizability

  - remove LOG_LEVEL_DEBUG_SAMBA
  - add a mask field for log levels
  - make the log levels customizable from the gui
settings: fix "Foo failed to start" notifications for disabled webserver/eventserver/jsonrpc server
Merge pull request #2661 from cptspiff/debug_custom

changed: improve logging customizability
[language] add location where string is used
Merge pull request #2603 from pieh/epggrid_dr

GUIEpgGridContainer: add dirty region processing and fixes for missbehaving memory freeing
[musicdb] fix: problems with building the unique index if users already have duplicates in the song table.
empty out all existing musicbrainz IDs from the song table (this is already done for artists/albums so a rescan is required anyway)
jsonrpc: some cosmetics in the JSON schema
jsonrpc: fix bad JSON objects in JSON schema
settings: add lost "None" option for the weather addon