Added a patch for Shell svn rev 33 that makes it build under GCC and ARM RVCT. Update...

Added a patch for Shell svn rev 33 that makes it build under GCC and ARM RVCT. Update ReadMe.txt to include optinal instructions to add the patch. This patch does not fix all the case issues in the Shell, but it does name all files in a consistent way so fixing the file name in the file system should fix any build issues on a case sensative file system. Fixing case bugs was breaking the patch and I could not figure out how to make it work.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@9405 6f19259b-4bc3-4df7-8a09-765794883524