Bug fixes and added trails

I have updated my implementation of Conway's game of life to fix a glitch that caused the application to freeze for 7 seconds. I have added new features such as trails. Trails are purely for visual effects and they do not disappoint! In the launcher there are new settings to change the speed of the cells and to enable/disable trails. I have also added a button on the launcher to pick you own colour for the trails; if you dont click the choose colour button but sill have trails enabled, the trail will use the default blue/green.