Also add script to update both server and apps

Signed-off-by: Jan-Christoph Borchardt <hey@jancborchardt.net>

build/update.sh

+#!/bin/bash
+# Update Nextcloud server and apps from latest git master
+# For local development environment
+# Use from Nextcloud server folder with `./build/update.sh`
+
+# Update server
+printf "\n\033[1m${PWD##*/}\033[0m\n"
+git checkout master
+git pull --quiet
+git --no-pager log -3 --pretty=format:"%h %Cblue%ar%x09%an %Creset%s"
+printf "\n"
+git branch --merged master | grep -v "master$" | xargs --no-run-if-empty git branch -d
+git fetch --prune --quiet
+git submodule update
+
+# Update apps
+source ./build/update-apps.sh