Added SQLite mappings

ISQLiteConnection and ITableMapping
Optional parameters allowed again!
BestSellers building - table changes
Sqlite WP7 Community Working?
Sqlite Updates - for WP7
Merge pull request #129 from asednev/vnext

Added SQLite mappings
Fix for abstract bindable SimpleTableViewSource
Merge branch 'vnext' of https://github.com/slodge/MvvmCross into vnext
Annoyingly VS2010 and VS2012 are fighting over the PCLs
Merge branch 'vnext' of github.com:slodge/MvvmCross into vNextDialog