Issue #1524816 by joachim: Added hook_hook_info() and moved hook implementations to new flag.flag.inc file.

Issue #1736352 by joachim: Changed hook_flag_flag() and hook_flag_unflag() to receive the flagging entity instead of the flagging id.

Issue #1720180 by joachim: Changed hook_flag_unflag() and Rules event to be invoked before the flagging entity is deleted.

Issue #1734494 by joachim: Added property to hook_flag_link_type_info() to let link types declare they provide a flagging entity form.

Issue #1699756 by joachim: Renamed info hooks: hook_flag_definitions() to hook_flag_type_info() and hook_flag_link_types() to hook_flag_link_type_info().

Replaced s/fcid/flagging_id/ throughout.

Replace s/\$content_ids\b/$entity_ids/ throughout.

Replace s/\$content_id\b/$entity_id/ throughout.

Issue #926252 by mooffie, snufkin: Added hook_flag_javascript_info_alter() to alter JavaScript info building and helper function to invoke it.