[feature/events] Add users_overview_options acp template event

PHPBB3-9550
[feature/events] Adding simple_header_head acp template event

PHPBB3-9550
[feature/events] Adding simple_footer_end acp template event

PHPBB3-9550
[feature/events] Adding forums_normal_settings acp template ledge

PHPBB3-9550
[feature/events] Add overall_header_index_link_left event

As a portal is of higher presdence than the board, unlike most extensions
it has a link before the board index link. This event satifies that.

PHPBB3-9550
[feature/events] Fix index_link_prepend template event

PHPBB3-9550
[feature/events] Adding viewtopic_topic_title_prepend template event

PHPBB3-9550
[feature/events] Correct template calls

There where two `<!-- LEDGE ... -->` calls in the templates left.
Replace those two calls with the proper `<!-- EVENT ... -->`
call

PHPBB3-9550
[feature/events] Adding acp prefix to acp event names

PHPBB3-9550
[feature/events] Add append to event name

PHPBB3-9550
[feature/events] Rename event to show location around copyright

PHPBB3-9550
[feature/events] Add overall_footer_copyright_after template event

PHPBB3-9550
[feature/events] Adjust to use prepend, not before

PHPBB3-9550
[feature/events] Add location (prepend) to event name

PHPBB3-9550
[feature/events] Rename event_main_actions to acp_main_actions

PHPBB3-9550
[feature/events] There is nothing between head and body.

PHPBB3-9550
[feature/events] Append "_append" to acp_forums_normal_settings

PHPBB3-9550
[feature/events] Fix names of events in adm/style/acp_main.html

PHPBB3-9550
[feature/events] Append "_append" to acp_users_overview_options

PHPBB3-9550
[feature/events] Change _end suffix to _after in acp_overall_footer_end

PHPBB3-9550