Support non-standard Minecraft installations

[llbit]

Minecraft is usually installed at a predictable location. For example %APPDATA%\.minecraft on Windows. However we need to support non-standard Minecraft installations.

• Ideally, if Minecraft is not found the user should have a chance to provide a custom location.
• The Minecraft install location should be stored in the Chunky settings file
• In the future the Chunky launcher should take care of this Chunky Launcher #164

[AEnterprise]

this can be done easely for the moment, if the non-standard minecraft installation is put in a folder named .minecraft you open a command promt and go to the parenting folder of that .minecraft folder then you do:

set appdata=%cd%

then run chunky from the same command prompt (chunky settings will be reset and created in that folder)