Update and rename DrawPanel.java to Interface.java

- Renamed DrawPanel.java to Interface.java
- Updated the user interface to account for point detection after drawing of the polygon
- Minor tweaks to the interface and buttons
Update and rename Gui.java to PolygonArea.java

- Renamed to PolygonArea.java
- Updated to handle drawing of the polygon and ray casting functionality
Update and rename MouseHandler.java to MouseClickerjava

- Renamed to MouseClicker.java
- Updated the mouse handler to account for ray casting
Merge pull request #3 from MichaelFisherECU/point-detection-feature

Point detection feature