Added ability to open SamReader from string, specifying either a URL or a file path.
This will make it easier treat INPUT parameters in Picard tools uniformly regardless of whether they designate a file or URL resoures.
Url detection and decision of whether the resource is file based on url based is done in SamInputResource.
Merge pull request #125 from iliat/ga4gh-work

Added ability to open SamReader from string, specifying either a URL or ...