Fix for issue #376

[yurikrivosheyev]

This PR introduces the IgnoreAssembly method that checks if an assembly should be ignored on Plugins and Workflow assemblies import tasks. If the 'solution prefix' command line argument is specified it is used for assembly name matching and matched assemblies are deployed. If no solution prefix is provided or an assembly does not match the prefix it is matched against a list of ignored publishers via a regex. So it's a 'white list' - 'black list' scheme for assembly checking before deployment. If solution prefix is provided we can do 'white list' check, if no prefix is provided or an assembly didn't pass this check, a 'black list' check is conducted using the ignored publishers list.
A few points to highlight:

• the ignored publishers list is a more general scheme compared to existing ignored assemblies list and is less likely to require extension in the future,
• all assemblies in the current ignored assemblies list will be matched when doing ignored publishers list check so this solution is backwards compatible,
• the IgnoreAssembly method is backwards compatible since it does not require solution prefix to work and without it it will work like existing ignored assemblies list.