Increment build number, per build

[macmule]

Pinched from AutoDMG & added to AutoCasperNBI, add to build phase:

Helps when testing & people are compiling own versions:

#
# Sets the version string to a monotonically increased string, based on
# the number of git commits.

set -o errexit
set -o nounset

VERSION=$(git --git-dir="$PROJECT_DIR/.git" --work-tree="$PROJECT_DIR" log | grep '^commit' | wc -l)
/usr/libexec/PlistBuddy -c "Set :CFBundleVersion $VERSION" "$TARGET_BUILD_DIR/$INFOPLIST_PATH"```

[macmule]

Added to build phase in 2.20.11 branch