Bumps the internal, technical version number of an iOS App, and creates and pushes a git tag with the new version number.

bump_version.sh

#!/bin/sh
agvtool next-version -all
NEW_VERSION=`agvtool what-version -terse`
MARKETING_VERSION=`agvtool what-marketing-version -terse1`
# Generate release notes by taking commit messages prefixed with TF: from git since last tag.
git log `git describe --tags --abbrev=0`..HEAD --format=%B | grep "^TF:" | sed 's/TF:/-/g' > whats-new.txt
git commit -am "Version bump to $NEW_VERSION"
git tag "$MARKETING_VERSION-build-$NEW_VERSION"
git push --tags origin master