Make it easy to add other programming languages

[mpartel]

We have special-case support for Java, C and Maven. It would be nice if things were more pluggable.

Relevant components:

• test scanner
• test runner
• merging of submission and server files
• preparation of stub and solution zips
• sandbox installed programs
• IDE plugin support

[jamo]

I would forget plugin support for now, but keep it in mind when designing this.

[mpartel]

There is something very preliminary for this in https://github.com/testmycode/tmc-langs

[jamo]

Tmc langs is soon used in NB client, and hopefully migrated to the server in near future.