[ticket/11688] Purge TWIG cache

Purge directories
Replace opendir() with DirectoryIterator

PHPBB3-11688
[ticket/11688] tpl_ files are no longer used

Remove tpl_ and ctpl_ from cache->purge() because those prefixes
are no longer used.

PHPBB3-11688
[ticket/11653] generate_text_for_display on mcp/mcp_topic.php

sub-task of ticket PHPBB3-11635:
find and fix all bypasses of generate_text_for_*

PHPBB3-11653
[ticket/11655] generate_text_for_display on ucp_pm_viewmessage.php

sub-task of ticket PHPBB3-11635:
find and fix all bypasses of generate_text_for_*

PHPBB3-11655
[ticket/11655] wrong var names for the uid and for the bitfield

sub-task of ticket PHPBB3-11635:
find and fix all bypasses of generate_text_for_*

PHPBB3-11655
[ticket/10037] Apply attached patch with a few changes

PHPBB3-10037
[ticket/11688] Rename purge_dir to remove_dir

PHPBB3-11688
[ticket/11688] Fix docblock

PHPBB3-11688
[ticket/10037] Fix table in subsilver2

Thanks, nickvergessen! ;-)

PHPBB3-10037
Merge pull request #1563 from cyberalien/ticket/11688

[ticket/11688] Purge TWIG cache
Merge remote-tracking branch 'Elsensee/ticket/10037' into develop-olympus

* Elsensee/ticket/10037:
  [ticket/10037] Fix table in subsilver2
  [ticket/10037] Apply attached patch with a few changes
Merge branch 'develop-olympus' into develop

* develop-olympus:
  [ticket/10037] Fix table in subsilver2
  [ticket/10037] Apply attached patch with a few changes
[ticket/11655] Use $parse_flags

sub-task of ticket PHPBB3-11635:
find and fix all bypasses of generate_text_for_*

PHPBB3-11655
[ticket/11653] Use $parse_flags

sub-task of ticket PHPBB3-11635:
find and fix all bypasses of generate_text_for_*

PHPBB3-11653
[ticket/11653] Missing ";"

sub-task of ticket PHPBB3-11635:
find and fix all bypasses of generate_text_for_*

PHPBB3-11653
[ticket/11653] Use $parse_flags

sub-task of ticket PHPBB3-11635:
find and fix all bypasses of generate_text_for_*

PHPBB3-11653
Merge remote-tracking branch 'brunoais/ticket/11655' into develop

* brunoais/ticket/11655:
  [ticket/11653] Use $parse_flags
  [ticket/11653] Missing ";"
  [ticket/11655] Use $parse_flags
  [ticket/11655] wrong var names for the uid and for the bitfield
  [ticket/11655] generate_text_for_display on ucp_pm_viewmessage.php
Merge remote-tracking branch 'brunoais/ticket/11653' into develop

* brunoais/ticket/11653:
  [ticket/11653] Use $parse_flags
  [ticket/11653] generate_text_for_display on mcp/mcp_topic.php
[prep-release-3.0.12] Bumping version number for 3.0.12-RC2.
[prep-release-3.0.12] Update Changelog for 3.0.12-RC2 release.