[PATCH 1/3] - Add GIT Version number

Add a version number to the GIT Makefile; lifted from the Linux kernel
source.  Once set, the version number will be reported by the "--version"
option on git commands that are converted to argp argument processing.

The version number was arbitrarily set to 0.5.0 as a starting point, but
obviously you can change it as you see fit.

Signed-off-by: Sean Estabrooks <redacted>