Remove serializable from test results.
Add code to collect files with no extension.

Many test files are of the form file(SL|PP|RT) instead of file.vdm(sl|pp|rt).
The provider now recognizes and collects these files.
Remove jar plugin version (defined in root pom).
Implement parsing of files without extensions.

The file is inspected and a virtual extension is created from the
last 2 characters. This allows parsing to proceed normally.
Support for interpreter tests on new framework

The String Result format adapts the current format of
interpreter tests.

The ParamTest behaves like the CommonInterpreterTest.
Remove unused imports
Actual interpreter tests using new framework
Fix handling of entry files for classicRT test.
Mark cmrt resource for skipping.
Print actual result when result file is missing.
Add util method for interpreting an AST.
2 minor improvements to test executor

* Use AST intepretation instead of reparsing.
* Print actual result if the result file is missing.