Introduced VistaDB dialect

Also tests copy-pasted from SqlServer ones
Made some tests pass
Made all SqlServer tests pass for VistaDb4
Merge remote-tracking branch 'upstream/master'
Made VistaDB provider build
VistaDB4 provider cloned to VistaDB5 provider

Also added separate tests project
VDB5 provider optimized to use new dbms features
Default extension for VistaDB5 provider is vdb5
Update VistaDB4Expression.cs

Fixed expression parsing for Equals method on column (argument formatting and null check were missed).
Update VistaDB5Expression.cs

Fixed expression parsing for Equals method on column (argument formatting and null checking were missed).
Merge remote-tracking branch 'upstream/master'
Merge branch 'master' of https://github.com/ilyalukyanov/ServiceStack.OrmLite
Merge remote-tracking branch 'upstream/master'
Merge branch 'master' of https://github.com/ilyalukyanov/ServiceStack.OrmLite
Merge pull request #394 from ilyalukyanov/master

Added VistaDB4 and VistaDB5 support