Fix: Replace deprecated -extdirs option with -cp in JDK 9+

[Jxpro]

This PR is to solve the following problem: In JDK 9 and above, the -extdirs option to specify additional class library directories is no longer supported. JDK 9 Release Notes: https://www.oracle.com/java/technologies/javase/9-relnotes.html

The following quote is from PR #97

issue related:

• resolves Compilation error on windows 10 #95
• resolves Not able to compile: "error: option -extdirs not allowed with target 15" #94
• resolves problem with compiling the .bat files #72

And the -cp option is also compatible with jdk8, as shown in the figure:

[akeranen]

Thank you! I think it's about time we address this issue.

[adalberto1986]

I would like to know if it is possible in the one to simulate with drones, and what would be the settings