World Map Screen

The World Map Screen now has a background map image and 4 clickable
buttons that take the user to the same farm.
Merged with the current Master
Attempt to fix the android timer bug.
Final Map changes

When clicked, a farm displays seasons.
When play is selected, the correct farm with the correct season starts.
Graphics have been updated.
Merged with the current Master
Inventory is displaying

Inventory is displaying
Javadocs added
World Map method wasn't being called
FarmAdventure Singleton

Made FarmAdventure into a Singleton
Fixed timing events for season and game end.
Merge branch 'master' of https://github.com/AA-Software/farm-adventure
Timer fixed and Leaves fixed

Timer for seasons officially works. Leaves do not appear on water plots.
Inventory display and Buy enable

Inventory is now displaying item name, quantity in the inventory,
price, buy, and sell buttons. Only the buy button is enabled (items are
added to the inventory). However, purchases are not reflected in the
inventory view.
Implemented over-time tools
First round of irrigation changes.

- Irrigation now runs on an EnumSet.
- To get Irrigation texture, use getIrrigationTextureName()
Round two of irrigation changes.

- Still need to add images for BOTTOM, LEFT, and RIGHT.
- IrrigationListener isn't getting called for some reason...
Round three of irrigation changes.

- Fixed problem with IrrigationListener by re-applying the input
processor to the stage after clearing.
- Fixed two bugs that were causing NullPointerExceptions in the
getIrrigationChoices method.
Round 4 of irrigation changes.

Left to do:
* If currIrr is empty, should check all surrounding
* Doesn't have correct graphics for bottom, left, right
* Doesn't update neighbor squares (water squares should also take part)
Round 5 of Irrigation Changes
Finished irrigation.