WIP put project and sub-project filter values in list.
Made project service for (sub)projects. Can use sub-project filter.

There is an existing bug that prevents sub-project filtering working, will look into that now. Also still need to know before hand if there are any sub-projects so we can hide the filter if there are none.
Wried up filtering by project on non-project work packages view.
Removed sub project filter from general wp view.

filtering on sub-projects does in fact work, it's just that it always also includes the parent project so it doesn't become apparent until you have to different sub projects.
WIP. Custom fields appearing in filters section but for some reason not filtering.
Fixed bug in query model which was preventing custom fields being available.
Small change to get custom fields of type list to be filterable.
Using query service call in filter model instead of default filters.
Fetching app wide custom value filters and caching values per project.
Merge branch 'dev-angular-filter-by-project' of github.com:opf/openproject into dev-angular-filter-by-project

Conflicts:
	app/assets/javascripts/angular/helpers/components/path-helper.js
	app/assets/javascripts/angular/models/query.js
	app/assets/javascripts/angular/services/query-service.js
	app/controllers/api/v3/queries_controller.rb