Rename 'VA {Gold Disk => Enterprise VistA}'

Replace all occurrences in README.rst files using bash code:

 git grep -li gold -- '*.rst' |
 while read readme; do
   tr $'\n' $'\r' <"$readme" |
   sed $'s/-\rVA Gold Disk\r-/--------\rVA Enterprise VistA\r--------/' |
   tr $'\r' $'\n' >"$readme.tmp" &&
   mv "$readme.tmp" "$readme"
 done

Replace occurrences in Scripts/MCompReposReadMeGenerator.py by hand.

Change-Id: Ia17f47257ff75e62a4ee6d621e307f6c2ed7f575