Implement multicall support by using an sqlite database to store and
retrieve calls. Two interfaces have been added:
1) add-call.php. Used to add calls.
example: add-call.php 15555555555 '0 10-16 * * *' 'http://www.domain.com/xml.xml'
2) create-table.php. Creates the database file
Created calls are retrieved in the caller.php file. Each call is run
through the scheduler to verify if it is time for it to be made.
Implement a scheduler based on crontab to execute calls at specific
times. Using PHP-Cron, we can implement a single cron at the system
level and then use methods to add cron jobs at the PHP level. This
allows eventually expansion to handling multiple song calls.
