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

symfony.lock

@@ -53,9 +53,6 @@
             "ref": "44d3aa7752dd46f77ba11af2297a25e1dedfb4d0"
         }
     },
-    "doctrine/doctrine-cache-bundle": {
-        "version": "1.3.2"
-    },
     "doctrine/doctrine-fixtures-bundle": {
         "version": "3.0",
         "recipe": {
@@ -678,9 +675,6 @@
     "symfony/templating": {
         "version": "v4.1.1"
     },
-    "symfony/thanks": {
-        "version": "v1.0.7"
-    },
     "symfony/translation": {
         "version": "3.3",
         "recipe": {
@@ -723,15 +717,6 @@
             "ref": "6bdfa1a95f6b2e677ab985cd1af2eae35d62e0f6"
         }
     },
-    "symfony/web-server-bundle": {
-        "version": "3.3",
-        "recipe": {
-            "repo": "github.com/symfony/recipes",
-            "branch": "master",
-            "version": "3.3",
-            "ref": "dae9b39fd6717970be7601101ce5aa960bf53d9a"
-        }
-    },
     "symfony/webpack-encore-bundle": {
         "version": "1.0",
         "recipe": {