Make TT's INCLUDE_PATH always point to app's views directory

In the "Views" section Dancer/Cookbook.pod reads "You can change this location by changing the setting 'views'." But if you are using TemplateToolkit, the INCLUDE_PATH is not getting changed. This means that if you change 'views' setting, any nested sub-templates included via INCLUDE or PROCESS directives will be served from the old initial 'views' directory. This is probably not the way it is supposed to work, is it?

This fix makes INCLUDE_PATH point to the same location as the app's 'views' setting.