Added custom RetroCake Install Directory settings

Version bump to 1.3.0
On first startup the program will ask you if you want to have a custom install dir
This installs the supportive system to your custom dir instead of C:\RetroCake
If you say No to custom installation it will default to C:\RetroCake as normal.

Whenever RetroCake program is started it will pull the custom install directory and not ask anything about it.
Dummy check file is in C:\Users\username\Appdata\Roaming\RetroCake\CusInstallDir.txt
Do not change this file D: