added project start and end date (#1303)

* added sortable js library
* activity in invoice is optional
* added javascript widget for paginated boxes
* fix activity dropdown for globals only
* added timesheet service to reduce code duplication
* use repository to query for teams in dropdowns
* added project validator
* validate project start and end against timesheet
* include begin and end in dynamic form requests for projects
* added timezone and language option to import flag, improve timesheet import speed
* deactivate cross-timezone filter
* add virtual fields to field order list
* composer update
* added param to ignore dates
* position loader icon fixed - fixes #1330
* permission problem when creating a new project - fixes #1340
* remove dev dependencies webserver and thanks bundle
* stop information leak (begin and end date) in duration mode - fixes #1307
* unify timesheet edit dialog for user and admins
* fix security issue, own rates exposed to unauthorized users in multi-update dialog

yarn.lock

@@ -6583,6 +6583,11 @@ sockjs@0.3.19:
     faye-websocket "^0.10.0"
     uuid "^3.0.1"
 
+sortablejs@^1.10.1:
+  version "1.10.1"
+  resolved "https://registry.yarnpkg.com/sortablejs/-/sortablejs-1.10.1.tgz#3d52b00f871be00f00f84d99a60d120bf3dfe52c"
+  integrity sha512-N6r7GrVmO8RW1rn0cTdvK3JR0BcqecAJ0PmYMCL3ZuqTH3pY+9QyqkmJSkkLyyDvd+AJnwaxTP22Ybr/83V9hQ==
+
 source-list-map@^2.0.0:
   version "2.0.1"
   resolved "https://registry.yarnpkg.com/source-list-map/-/source-list-map-2.0.1.tgz#3993bd873bfc48479cca9ea3a547835c7c154b34"