Issue #2937659 : post in a public group should always have public visibility

Issues #2945370 by serhiy-chornobay: Fix problem with iPhone the keyboard keeps hovering above the comment field

#2929953 Waves: JS errors in IE11 for menus

#2931073 - Click events are swallowed by SVG <use> elements in IE/Edge

DS-4871: Fatal error occurs when clearing caches via CLI on multilingual installs

2929953 by left: adjust behat test condition to look at path not element for PM, in reaction to failing test due to the svg pointer event being set to none

DS-4825: Improve and extend behat test for multilanguage

* DS-4632 by left: add overlay with gradient to hero element, wrap intro content in blockquote, styls to reflect, vertical align hero content on mobile

* DS-4632 by left: tweak activity overview icon and font style, align both columns, always wrap main block in primary div for max width of 2/3, align readmore by adding primary selector

* DS-4632 by left: teaser background on image wrapper from grey to brand primary

* DS-4632 by left: replace topic icon, add landing page icon, gulp sprite-icons

* DS-4632 by left: edit reference to icon for user in activity overrview, remove fine control rule for topic icon

* DS-4632 by left: add icon to landing page teaser template, change bg colour of teaser image wrapper

* DS-4632 by left: delete preview css, mistakenly generated

* DS-4632 by left: reset teaser image wrapper to grey background

* DS-4632 by left: replace topic icon, generate icon sprite

* DS-4632 by left: replace topic icon, generate icon sprite

* DS-4632 and 4791 by left: add conditional for teaser image in templates, if no teaser image add hr

* DS-4632 and 4791 by left: add hr style for no teaser image

* DS-4632 by left: replace topic icon, generate icon sprite

* DS-4632 by left: add featured viewmode to viewmode array in node preprocess function to use same date format on featured items as teasers

* DS-4869 by bramtenhove: Remove permission to add languages for SM

* DS-4870 by bramtenhove, chmez: SM can translate account and site settings, remove ability if one language is available

* DS-4870 by bramtenhove: Add check in user form for user language negotation setting and fix coding standards

* DS-4870 by bramtenhove: Fixed test due to changes in user language negotation

Issue #2932356 by alex.ksis: Allow to find and fill WYSIWYG editor by name, label, placeholder or id (#689)

Issue #2938779 - add the PM e-mail notification setting only when module is enabled

* Issue #2939377 by left: part 1 css fix, add max height to ul elements, and vertical scroll, add as socialbase library

* 2939377 by left: add position option with collision flip to autocomplete, from jquery ui, which detects where the list overflows the viewport and changes position accordingly

* 2939377 by left: set max-height equivalent to 8 users in the list, then create vertical scroll, remove overflow hidden from main-container on mobile only, so select list does not get cut off but whole page grows to fit

* 2939377 by left: experiment with collision options

* 2939377 by left: remove bottom margin from autocomplete list, remove padding from li items and place on anchor instead, to better display the keyboard active item with background css, move rules from mentions css to autocomplete css where relevant

* 2939377 by left: remove collision and minLength in favour of adding conditional based on detecting if the userlist height exceeds the space between the bottom on the document and the textarea. If condition is met, add css positioning on userlist to place it above the textarea. Wrap all in conditional for viewport width > 600

* 2939377 by left: add rule for placement of user list above textarea

* 2939377 by left: remove jquery css method and replace with add class method. Move declarations into css rule in autocomplete css. This corrects behaviour of unwanted list placement when it is opened a second time, as the top position set in the css method gets overrideden by jquery ui behaviour

* 2939377 by left: remove margin-bottom on autocomplete and add to mentions css instead, for mobile only. Space between userlist and bottom of page indicates to user that all users are visible in list

DS-4825 by chmez: Use the directory of temporary files for storage translations and fix to interrupt of a batch process.

Issue #2938779 by jaapjan, jochemvn: add the private message e-mail notification setting when module is enabled only.

* Issue #2936748 by jaapjan: prevent warning when adding node from group page with social tagging.

* Issue #2936748 by jaapjan: remove unused use statements.

Issue #2940839 by Namzhilma Zhambalova, bramtenhove: Error: Call to a member function hasPermission() on string in social_post_comment_create_access() (#737)