Replaced '_materialItem' with '_materialItemArray' in MainActivity.java.

To clarify that its an array not a single item.
Replaced '_facilityItem' with '_facilityItemArray'

To clarify its an array not a single item.
Replaced '_item' with '_itemArray' in MaterialListAdapter.java.

To make it clear its an Array not a single item.
Fixed material selection dialog bug.

The Problem:

    The previous implementation relied on a 1-to-1 mapping
between the MaterialListAdapter's data array and the _materialNames
array. But when a user clicked an item in the dialog it removed that
item from the Adapter's ArrayList and destroyed the 1-to-1 mapping.

    The result was if you selected materials from in order, always
selecting the one at the top, it would always load _materialNames[0]
("Oil") into the materials textview.

The Fix:
    Grabbed the right string before removing the item from the
Adapter's data ArrayList.
Merge pull request #10 from aelx311/david-dialog-fix

Fixed bug with material selection dialog