Fix #304 Too many open files

As the HttpClient's handler is not shared anymore, we need to ensure that the HttpClient is disposed after done using it.
Bump nuspec to 0.9.5-pre10
Updating version to 0.9.5

Getting ready to push out for 0.9.5
Set nuspec version to 0.9.5

* Set nuspec version to 0.9.5
* Add nuget build instruction to packaging readme
Fix #307 TestParsePersonaAssertion failed (Rework)

Use 'Email:Site' string as a key to store an assertion in the assertions dictionary