Remove CTK_BASE_ variables and explicitly specify target and include dirs

The ctkMacroBuildLib macro has also been simplified to set the variable
cache property ${PROJECT_NAME}_INCLUDE_DIRS that can now easily be re-used.
Merge branch 'simplify-build-system'

* simplify-build-system:
  Remove CTK_BASE_ variables and explicitly specify target and include dirs
Fix default value for AdditionalLauncherSettings settings

This commit updates the default value for AdditionalLauncherSettings
to be an empty string. The default value is now consistent with
Slicer expectation where the settings file is suppose to have the name
ApplicationName-Rev.ini if no user setting basename is specified.

Fixes #45
Fixes Slicer issue 3730 - See http://na-mic.org/Mantis/view.php?id=3730
Merge branch '45-fix-default-for-userAdditionalSettingsFileBaseName'

* 45-fix-default-for-userAdditionalSettingsFileBaseName:
  Fix default value for AdditionalLauncherSettings settings