Merge pull request #64 from luryco/master

Add the "J" Format to DicomTag.cs
Added virtual methods to DicomService so derived objects can specify the Stream used to write received SopInstances to during CStoresSCP.  Also added some documentation
Merge pull request #66 from chafey/master

CStoreSCP changes to add flexibility for how received SopInstances are handled
fix loading of temp files in default implementation of GetCStoreDicomFile()