add script for automatically setting build version from git tag

Scripts/set_build_number.sh

@@ -0,0 +1,23 @@
+#!/bin/bash
+
+# taken from blog post: http://www.mokacoding.com/blog/automatic-xcode-versioning-with-git/
+# Automatically sets version of target based on most recent tag in git
+# Automatically sets build number to number of commits
+#
+# Add script to build phase in xcode at the top of the chain named "set build number"
+# put this script in the root of the xcode project in a directory called scripts (good idea to version control this too)
+# call the script as $SRCROOT/scripts/set_build_number.sh in xcode
+
+git=$(sh /etc/profile; which git)
+number_of_commits=$("$git" rev-list HEAD --count)
+git_release_version=$("$git" describe --tags --always --abbrev=0)
+
+target_plist="$TARGET_BUILD_DIR/$INFOPLIST_PATH"
+dsym_plist="$DWARF_DSYM_FOLDER_PATH/$DWARF_DSYM_FILE_NAME/Contents/Info.plist"
+
+for plist in "$target_plist" "$dsym_plist"; do
+  if [ -f "$plist" ]; then
+    /usr/libexec/PlistBuddy -c "Set :CFBundleVersion $number_of_commits" "$plist"
+    /usr/libexec/PlistBuddy -c "Set :CFBundleShortVersionString ${git_release_version#*v}" "$plist"
+  fi
+done