Updated the OmniGroup subproject to 40fbf9d1a0f565be127fc8c8ce3e665da2ea3a4e.
Updated the linked frameworks per linkage requirements of updated OmniGroup frameworks.
Updated GraphSketcher-Mac to build with OmniInspector changes in the updated OmniGroup frameworks.
Updated the build system requirements.
Fixed issue where the generated Archive was empty.

Locally override the value of INSTALL_PATH that we picked up from the Omni
xcconfig file which was causing the generated Archive to be empty.
Fix for issue #11: Can't archive for for App Store Upload

Rework how the GraphSketcherModel headers are copied so they are in an
accessible location when generating the PCH during a Release+Archive build.

Locally override the value of INSTALL_PATH that we picked up from the Omni
xcconfig file which was causing the generated Archive to be empty.