Added the '--java' CLI option
Added the '--java' CLI option

The '--java' CLI option let users specify the Java executable to be used.
This is because recent MC version need Java 1.8+, and users may have other
applications tied to an older version.

Khroki/MCEdit-Unified,fhfuih/MCEdit-Unified,Khroki/MCEdit-Unified,Khroki/MCEdit-Unified,fhfuih/MCEdit-Unified,fhfuih/MCEdit-Unified