Changes

Add a formal grammar using ANTLR

This uses a combined ANTLR3 and ANTLR4 grammar (the differences are
converted from ANTLR3 to ANTLR4). ANTLR4 is used to run the grammar
easily, and ANTLR3 to analyze the grammar to verify it is LL(k=2).

- `extends_clause` was fixed compared to the 3.4 grammar
- `array_arguments`: Changed to use iteration as the rest of the grammar
- `function_call_args` have been rewritten due to #2250 and also resolves
  ambiguity with named arg or expression
  f(a, b=3) ANTLR4 said "f(a, b" parsed, expecting ")"
- `der_class_specifier` was merged into `short_class_specifier` to get
  k=2 instead of k=3.
- TODO: `equation` resolved the ambiguity by allowing simple expressions
  stand-alone. This is easy to implement for all tools, might be OK for
  flat Modelica, but is usually a user error... How to resolve it? Use
  ANTLR backtracking or predicates? Create a simple_expression_no_cref?

Fixes

- [ ] Changed `import_clause` to include `.*` explicitly as it is
  a different lexical token than `.` `*`.
- Fixed S_CHAR to be a fragment (broke during ANTLR 4 to 3 conversion)
- Added a docker image with some libraries to test the parser on

WIP see if Jenkins strips CLASSPATH env.var

WIP set CLASSPATH

WIP add . to CLASSPATH

Change grammar for function calls back to as written in the specification

fix .CI/Jenkinsfile conflict