(#57) Strips leading `v` from generated version numbers

With this change, the `build-bundle-file.sh` script constructs a shell script that parses the git version numbers a bit differently so that the `rebuild_iso.sh` script will generate version numbers that are more consistent with how our version numbers used to look when that script is run with no arguments (previously, our Microkernel versions where simply numbers like "0.9.3.0", but with changes in the Microkernel build process made in late November and early December of 2012, this script was generating ISO files with versions that look more like "v0.9.3.0" instead).  This change will remove the "v" prefix from the start of these versions (so that even though a tag of "v0.9.3.0" is used in the GitHub repository, the version number used in the ISO that is built from the repository contents will be "0.9.3.0".