Describe the contribution
Fixes #103, implemented the ability to allow users to select the header version byte offset, or custom offsets. In order to support this, some relatively major changes had to be implemented:

• A Python-native "mini" cmdUtil to send UDP data. The GroundSystem app in its current form is no longer dependent on the external C cmdUtil app (also fixes cFS ground system GUI Python code should generate cmd UDP directly #61, at least partially)
• Using Python's mmap module to share data between processes

Testing performed
Steps taken to test the contribution:

1. Make changes to code
2. Run program to verify functionality

Expected behavior changes
The update allows users to change the byte offsets for sending commands and parsing telemetry, to support different header versions or other implementations of cFS

Additional context

• Note that the "mini" cmdUtil is only a subset of cmdUtil's full functionality. Should the GroundSystem app be updated in the future, the full cmdUtil might need to be used again, or the "mini" cmdUtil updated accordingly
• There is a larger issue regarding the GroundSystem app as a whole and interprocess communication (IPC). There are multiple techniques to achieve this, but which technique is preferred, and whether or not GroundSystem should be completely redesigned to avoid IPC in the first place, is a discussion for the CCB.

Contributor Info - All information REQUIRED for consideration of pull request
Leor Bleier, NASA GSFC\Code 582