Resolves a compilation error reported with 2.11

2.11 doesn't compile case classes without parameters anymore.
Because the case class is not needed it is changed to a normal class.
Bump to the new plugin-profiles version.
Fixed source compatibility with Scala IDE master

Source compatibility with master was broken by this recent commit
scalaide/scalaide@cf73ce8. Furthermore, this patch depends on
https://github.com/scala-ide/scala-ide/pull/571
Merge pull request #196 from dotta/issue/update-code-to-compile-against-ide-master

Fixed source compatibility with Scala IDE master
Merge pull request #195 from dragos/issue/bump-plugin-profiles

Bump to the new plugin-profiles version.
Switch to plain Scala OSGi bundles.
Merge pull request #197 from dragos/improve/scala-osgi

Switch to plain Scala OSGi bundles.
Merge pull request #189 from sschaef/t-resolve-2.11-compilation-error

Resolves a compilation error reported with 2.11
Sets the version to 0.4.2

A new version is needed for Scala IDE 4.0.0-M1, but there is no major
changes with 0.4.1, so reverting to the 0.4.x branch.