eclipse

Describe the bug

Some devfiles have several commands that need to be executed in a precise order to succeed.
Some are named with prefixed numbers that help the user, but some others are not.

For instance:

• angular
• python-django

Che version

• latest
• nightly
• other: please spec

Document the commands that clients should implement and their expected behaviour on https://github.com/eclipse/eclipse.jdt.ls/wiki/JDT-LS-Extensions

Brief feature description

We should use cxx::function instead of cxx::function_ref in the cxx::unique_ptr. But when we do the transition it is likely that the custom deleter classes will remain since they will also work with cxx::function. This should be cleaned up since they are no longer required.

1. Replace cxx::function_ref with cxx::function
2. Remove custom deleter clas

Consider the following:

void meth(Closure closure) {
  closure.|
}

When invoking content assist (Ctrl+Space) at |, the methods and properties of groovy.lang.Closure are very low in the list of proposals. This is due to very-well-known type adjustments made within org.codehaus.groovy.eclipse.codeassist.proposals.AbstractGroovyProposal.getRelevanceClass().