Fixed an issue with one to many relations

As described in #2325
Fix css - added scrollbar on list view for small screens
Autocomplete changes:
Removed initSelection method in favour of directly setting the initial value
Added extra (not null) check autocompleteInput onChange function (prevents error when first called)
Merge pull request #2169 from antoinemineau/master

Fix css of list box on small screens (added scrollbar)
Merge pull request #2326 from caponica/autocomplete_refactor_init

Refactored how the autocomplete initialises its values
Minor improvements in translation messages in sonata_type_model_autocomplete
Merge pull request #2363 from pulzarraider/autocomplete_msg_excp_impr

Minor improvements in translation messages in sonata_type_model_autocomplete
Updated App.js from latest version of AdminLTE - added slimscroll
Fix overflowing long texts in add menu
Merge pull request #2358 from net02/patch-3

Fixed an issue with one to many relations
Added options to admin_type to allow to hide delete
Fixed typo in tab menu template
Merge pull request #2373 from Bladrak/fix_typo

Fixed typo in tab menu template
Removed problematic overflow CSS rules for ".box .box-body" in layout.css
Merge pull request #2374 from pulzarraider/overflow_fix

Removed problematic overflow CSS rules for ".box .box-body" in layout.css
Localize select2
Merge pull request #2380 from pulzarraider/localize_select2

Localize select2
Fixed minor typo in installation doc

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
Merge pull request #2372 from Bladrak/admin_type_hide_delete

Added options to admin_type to allow to hide delete
Merge pull request #2368 from pulzarraider/menu_overflow_fix2

Fix overflowing long texts in add menu