Update mod_shoutbox/tmpl/default.php

Get the value for the mass deletion

added input and submit button for mass delete

function for mass delete (J1.5 standards)

This function is using Joomla 1.5 coding standards. I have also added a comment out equivalent version of the function using Joomla 2.5 coding standards, however it doesn't seem to work.

Update mod_shoutbox/helper.php
Merge pull request #25 from wilsonge/new-feature

Add in Mass Delete Feature. Close #24. Thanks to Lodder for this