[ticket/11899] Give indication of activity after voting in poll.

PHPBB3-11899
[ticket/11935] Fix <p> tags not allowed inside <strong> tags

PHPBB3-11935
[ticket/11935] Fix incorrect alt tags that should be title tags

PHPBB3-11935
[ticket/11935] Fix stray </a> tags

PHPBB3-11935
[ticket/11935] Fix invalid HTML usage of <label> tag in prosilver

PHPBB3-11935
[ticket/11935] Remove obsolete table attributes from Prosilver

cellpadding, cellspacing, border are obsolete table attributes.
They are handled by CSS already using table and .table1

PHPBB3-11935
[ticket/11935] Replace obsolete table attributes in Admin with CSS

PHPBB3-11935
[ticket/11935] Tweak colour swatch table

PHPBB3-11935
Merge branch 'develop' into ticket/11935
[ticket/11525] Only remove group or user prefix from given avatar data

Until now, the user data had both user_id and group_id keys in the avatar
data. As both group_ and user_ prefixes were removed the group_id was
collapsed onto the user_id and therefore all users in the same group had
the same prefix for their uploaded avatars. This patch will make sure
that the correct id is used depending on whether it's a group's or user's
avatar data.

PHPBB3-11525
[ticket/11534] Check remote avatar content type if possible

This should make sure that error pages like 404 or 503 pages are not treated
as remote avatar images.

PHPBB3-11534
[ticket/11973] Remove logic from tokens language array

Previously if a translator did no translate a token, it would not be
displayed. On the other hand, the translator could add additional tokens
which have no functionality.  Functionality is already hardcoded into
bbcode.php so we can that in the ACP aswell, in order to prevent namend
issues.

PHPBB3-11973
[ticket/11928] Replace AJAX loading popup with animation.

PHPBB3-11928
[ticket/11928] Make sure the indicator is on top of other elements.

PHPBB3-11928
[ticket/11935] Merge remote-tracking branch 'upstream/develop'

PHPBB3-11935
[ticket/11928] Rename loadingAlert to loading_indicator.

PHPBB3-11928
Merge pull request #1840 from cyberalien/ticket/11030

Fix cursor in prosilver and ACP
[ticket/11746] The IN_PHPBB check is not necessary.

PHPBB3-11746
Merge pull request #1848 from prototech/ticket/11746

[ticket/11746] Add "admin activation required" notification
[ticket/11972] Add posting_editor_subject_after template event

PHPBB3-11972