bin: add fastRun.sh script for developers

Useful for developers, or users that know what they are doing. If you just
upgraded Etherpad version, installed a new dependency, or are simply unsure of
what to do, then before running this script, please execute bin/installDeps.sh
once.

Fixes #3711 (partially)

README.md

@@ -98,6 +98,8 @@ Documentation can be found in `doc/`.
 ## Things you should know
 You can debug Etherpad using `bin/debugRun.sh`.
 
+You can run Etherpad quickly launching `bin/fastRun.sh`. It's convenient for developers and advanced users. Be aware that it will skip the dependencies update, so remember to run `bin/installDeps.sh` after installing a new dependency or upgrading version.
+
 If you want to find out how Etherpad's `Easysync` works (the library that makes it really realtime), start with this [PDF](https://github.com/ether/etherpad-lite/raw/master/doc/easysync/easysync-full-description.pdf) (complex, but worth reading).
 
 ## Contributing

bin/fastRun.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+#
+# Run Etherpad directly, assuming all the dependencies are already installed.
+#
+# Useful for developers, or users that know what they are doing. If you just
+# upgraded Etherpad version, installed a new dependency, or are simply unsure
+# of what to do, please execute bin/installDeps.sh once before running this
+# script.
+
+set -eu
+
+# source: https://stackoverflow.com/questions/59895/how-to-get-the-source-directory-of-a-bash-script-from-within-the-script-itself#246128
+DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
+
+echo "Running directly, without checking/installing dependencies"
+
+# move to the base Etherpad directory. This will be necessary until Etherpad
+# learns to run from arbitrary CWDs.
+cd "${DIR}/.."
+
+# run Etherpad main class
+node "${DIR}/../node_modules/ep_etherpad-lite/node/server.js" "${@}"