Add a new prededined function fileExists

The `fileExists` function will return true if the file exists, false if it doesn't.
The parameter is either a `java.lang.String`, a `java.io.File` or a `java.nio.file.Path`.
Thierry Chantier joins as a contributor
Merge pull request #67 from titimoby/new_function_fileExists

New prededined function fileExists
Attach assemblies

This will allow distributing Golo release images to Maven Central instead of Sourceforge.
Support for varargs in dynamic object methods
Merge pull request #68 from jponge/wip/fix-dynobj-varargs

Support for varargs in dynamic object methods
Bye SourceForge
Fix Blanklines in Case and Match Branching

It was not possible to insert a blankline or comments inside Case and Match blocks.
To fix it, I just replaced the "(BlankLine())?" by "BlankLines()"
Merge pull request #69 from danielpetisme/fix-blanklines-in-case-match-branching

Fix Blanklines in Case and Match Branching
Fibonacci based on reflection
Reflection-based method dispatch evaluation

This includes dispatch based on vtables, and using Method references on a general type (Object in
our case).

This gives a good indication of the cost associated with reflection-based method dispatch for a
dynamic language runtime, but not for reflection in general.