Add watch.sh and update utils.sh

Signed-off-by: Severin Kaderli <severin.kaderli@gmail.com>

system/bin/watch.sh

@@ -0,0 +1,29 @@
+#!/bin/bash
+# 
+# SCRIPT NAME:
+# watch.sh
+#
+# AUTHOR:
+# Severin Kaderli <severin.kaderli@gmail.com>
+#
+# DESCRIPTION:
+# This script watches a file for changes and if it changes it
+# executes the given command.
+#
+# USAGE:
+# ./watch.sh FILE COMMAND...
+. utils.sh
+
+# The file to watch
+FILE="${1}"
+
+# The rest of the arguments is the command
+shift
+COMMAND="${@}"
+
+print_header "Watching ${FILE}"
+while inotifywait -qq -e close_write "${FILE}";
+do
+    print_log "File has changed, executing command"
+    $($COMMAND)
+done