introduce USE-OCL engine and track

[Morriar]

Some work in this PR:

• moved engine definition from frontend to Mission class
• created a editor proerty at the track/mission ini level
• introduce OCL engine
• introduce OCL editor for frontend
• introduce OCL track stub

[Morriar]

@privat can you

• install use-ocl
• add "use-ocl/bin" to the PATH on the test server please?

[privat]

seems good. need to install use-ocl in the Docker files. I will investigate

[Morriar]

test this please