Update for the upcoming plugin-profiles 1.0.5

Similar version bumps are expected to be added to
https://github.com/scala-ide/scala-ide-play2/pull/213
https://github.com/scala-ide/scala-search/pull/90
Merge pull request #188 from huitseeker/issue/plugin-profiles

Update for the upcoming plugin-profiles 1.0.5
Removes some dead code as a prereq for API work

unused members and imports, some deprecations
Merge pull request #189 from huitseeker/issue/API

Removes some dead code as a prereq for API work
Adapt to new ScalaPlugin APIs