WIP: Fixes for behaviors in ReSharper
Use IClrTypeName instead of sting in ReSharper runners
Dropping support for ReSharper 6
Tags/ReSharper Unit Test Categories are only determined on the ContextElement level and inherited to element below (Specification, Behaviors, Behavior Specifications)
Fixed determination of attribute base types when using ReSharper's Metadata API
Updated supported ReSharper versions in the readme
Preparing ReSharper runner to fix #17
Can now filter by test usages in find results
Fixing behavior specification runs, simplifying Task implementations a bit

i.e. BehaviorTask is not needed
Fixing ReSharper Unit Test Session restore with behaviors
Extracting invocation of IAssemblyContext into an ISpecificationRunListener
Reporting fatal errors only once
Moving RemoteRunListener back to its original namespace to ensure backward compatibility
Renaming file of PerAssemblyRunListener to match type name
Ensuring IAssemblyContexts are executed only once, even when running several contexts using one instance of the AssemblyRunner. Closes #17
Enabling full trust for assemblies loaded from remote sources (e.g. network shares)