startup performance optimization
Updated Firebird nuget.
Implemented Sql.GroupBy.None.
Fixed datetime format.
Added VS 2013 solution.
Migrated to VS 2013.
Fixed FW 4.5 ToString issue.
Fixed C# 5.0 compatibility issue.
Revert "Fixed C# 5.0 compatibility issue."

This reverts commit ec0bb8efa780b71f03aa7b9ded1b1d504f7b3291.
Revert "Fixed FW 4.5 ToString issue."

This reverts commit c82fdba0dafa941927316f59cf6de9e292a261ee.
Removed unnecessary proj and sln files.
Fixed Sybase DateTime2 compatibility issue.
Optimized load time.
Working on Assosiation/Union issue.
Formatting.
Fixed DB2 Bulk Copy issue.
Code formatting.
Resharper sattings.
Fix Oracle TimeSpan mapping.
Code formatting.