[ticket/10580] Remove checking of server timezone and DST when registering

Remove checking of server timezone and DST. It causes a problem by
selecting the wrong timezone when registering when the board_timezone is 1
hour less than the server timezone.

PHPBB3-10580
Merge remote-tracking branch 'Dickyf/ticket/10580' into develop-olympus

* Dickyf/ticket/10580:
  [ticket/10580] Remove checking of server timezone and DST when registering
[ticket/10569] Invalid string comparison in subsilver2

Fixing invalid string comparison in ucp_main_front.html in subsilver2

PHPBB3-10569
[ticket/10616] Add template inheritance to default styles

Adding template inheritance field to prosilver and subsilver2

PHPBB3-10616
[ticket/10616] Ignore template inheritance that points to self

Ignore template inheritance if it points to self

PHPBB3-10616
[ticket/10616] Add template inheritance to exported template

Add template inheritance when exporting template.cfg

PHPBB3-10616
[ticket/9914] Add backup warning to updater.

PHPBB3-9914
Merge remote-tracking branch 'unknownbliss/ticket/9914' into develop-olympus

* unknownbliss/ticket/9914:
  [ticket/9914] Add backup warning to updater.
[ticket/10512] Call startup.php from tests/bootstrap.php

PHPBB3-10512
[ticket/9831] Fix saving unchecked checkbox field value

PHPBB3-9831
Merge remote-tracking branch 'cyberalien/ticket/10616' into develop-olympus

* cyberalien/ticket/10616:
  [ticket/10616] Add template inheritance to exported template
  [ticket/10616] Ignore template inheritance that points to self
  [ticket/10616] Add template inheritance to default styles
[ticket/10569] Invalid string comparison in prosilver

Fixing invalid string comparison in ucp_main_front.html in prosilver

PHPBB3-10569
[ticket/10633] Stop leaking filename of attachments when thumbnail is requested

While filenames are chosen at random and there is no correlation between the
original filename and the new filesystem filename, there is a correlation
between filesystem filename and filesytem filename of thumbnails.

Adjust error message to no longer include the physical filename and make it
consistent with the error message that is shown when there is no attachment at
all.

This information was mostly useless for regular users (i.e. non-admins) anyway.

PHPBB3-10633
[ticket/10606] Fix incorrect hidden fields array name in page_header().

Regression from dfb7cc625a37c6345fa647ee3a21f890ba5c9649.

PHPBB3-10606
[ticket/10606] Also correctly use $s_search_hidden_fields in view(forum|topic).

Regression from dfb7cc625a37c6345fa647ee3a21f890ba5c9649.

PHPBB3-10606
[ticket/9084] Don't hide 'non-entered' dropdown CPF value if not required

PHPBB3-9084
Merge remote-tracking branch 'bantu/ticket/10512' into develop-olympus

* bantu/ticket/10512:
  [ticket/10512] Call startup.php from tests/bootstrap.php
Merge remote-tracking branch 'cyberalien/ticket/10569' into develop-olympus

* cyberalien/ticket/10569:
  [ticket/10569] Invalid string comparison in prosilver
  [ticket/10569] Invalid string comparison in subsilver2
Merge remote-tracking branch 'bantu/ticket/10606' into develop-olympus

* bantu/ticket/10606:
  [ticket/10606] Also correctly use $s_search_hidden_fields in view(forum|topic).
  [ticket/10606] Fix incorrect hidden fields array name in page_header().
Merge remote-tracking branch 'bantu/ticket/10633' into develop-olympus

* bantu/ticket/10633:
  [ticket/10633] Stop leaking filename of attachments when thumbnail is requested