Merge pull request #1 from Rhetos/master

Sync with original project
Working on implementation of RowPermissions concept, added first version
Fixed the bug in RP filter type resolution.
RowPermission for read implementation
* Made RowPermissions_AllowedItems a class in Rhetos.Dom.DefaultConcepts.Interfaces to be used as a FilterParameter for RowPermissions
* RowPermissions check will be done on materialized result data in batches of 2000 items
* Formatted and corrected exceptions
* Created tests for RowPermissions read functionality
RowPermissions inherits ComposableFilterBy, minor refactoring.
RowPermissions_AllowedItems filter parameter moved to DOM (Common.RowPermissionsAllowedItems).
Bugfix: Value-type filter without a given parameter value would fail even if the value is not used in the filter.
ApplyOnClientRead concept, for filters that are automatically added to each client request.
New concept ApplyFilterOnClientRead, a more flexible implementation of ApplyOnClientRead.
AddToLog action.
Improved use of ApplyFilterOnClientRead with RowPermissions.
If the read result is already filtered by row permissions filter, there is no need to check row permissions on the result data.
Reference constraint for Polymorphic (#23).
Merge branch 'master' of https://github.com/Rhetos/Rhetos
Release 0.9.19.