Lots of changes.
Merge branch 'master' of https://github.com/cgsmith/SimplePOS into dev
Added CSS and changed link structure to be friendlier.  (Better ux)
Added last day to Camper.
Link sales report to camper's individual transactions
PHPDoc addition
Stop execution after include is called.
Add closing report link to header.
Added code to handle success and errors if returned in the $result variable
Add functionality to sum non-tax and taxed items.  Check if sale went through.
Added functionality for a datepicker.
Created report for closing month.
Merge pull request #1 from cgsmith/dev

Dev