Update of Eclipse project files

- Update of project dependencies
- Deletion of scala-xml project
- Deletion of scala-parser-combinators project
- Update of .gitignore to match nested .cache files
Rework cff8b569 to heal the windows build.

 - change newTermName to fix negative length names
   rather than reject them
 - restore the old logic in unspecializedName for names that
   result from AnyRef specialized type parameters.

Why does fix the windows build? I remain none the wiser.
Merge pull request #2973 from sschaef/eclipse-update3

Update of Eclipse project files
Merge pull request #3013 from retronym/topic/unspec-fix-windows

Rework cff8b569 to heal the windows build.
Correct build command for scala-ide
Merge pull request #3015 from sschaef/eclipse-update

Correct build command for scala-ide