fixed: scraper fallback logic

code ended up selecting the default album scraper for artists
add new language string for sort title
python: extend CPythonInvoker to be able to handle interpreter initialization/deinitialization
python: introduce CAddonPythonInvoker to be used for python scripts run for addons
[win32] update VS project files
[osx/ios/atv2] - sync xcode projects
Merge pull request #3220 from cptspiff/fix_fallback_scraper

fixed: scraper fallback logic
Merge pull request #3214 from MartijnKaijser/sorttitle

add new language string for sort title
Merge pull request #3082 from Montellese/generic_python_invoker

python: move more logic from XBPython to CPythonInvoker
guilib: add input validation functionality to CGUIEditControl
settings: implement input validation for edit controls
CGUILabel: introduce <invalidcolor> support
smartplaylists: add support for input validation
[confluence] add <invalidcolor> for edit controls and in SettingsCategory.xml
[confluence] support invalid input in SmartPlaylistRule.xml
[win32] update VS project files
[osx/ios/atv2] - sync xcode project