Kotlin perspective added to Eclipse plugin.

 #KT-5355 Fixed
Package and units validation fixed.
Check if unit exists by OS methods, not by eclipse resources.
Update to Kotlin 0.8.232
Merge pull request #49 from JetBrains/fix_compilation

Update to Kotlin 0.8.232
Merge pull request #47 from adkozlov/elements-wizards

Kotlin perspective added to Eclipse plugin.
Change wizards and perspective icons
New Kotlin project wizard GUI created.

 #KT-5377 In Progress
New unit wizard page class refactoring.

Minor: name conventions
Default Kotlin perspective for all wizards.
SelectionListeners replaced with SelectionAdapters.
Refactoring: setErrorFormMessage -> validate.
Default project name is empty string.
Copyright added to NewProjectWizard.
AbstractWizardPage created, NewProjectWizardPage now extends the abstract one.
Constant strings refactoring.
Colon autoadding to label text.
GridData autocreating for controls.
Separator static factory method added.
Added method that checks creating object exists.