Merged with my version of the code

Removed redundancies in the code; some relics and most of all SD card
functionality.  Enabled mixing in the collection routine again simply
because pinching the air supply for so long was unwise.
Added php interface code to repo
Fixed incorrect naming of php files, added graphs

The display.php and interface.php were mixed around in the repo.
Resolved this issue and updated display.php to display a graph of the
run using pChart.
Added functionality for prototype valve
Merge pull request #1 from gauravg11/master

Code merging