mod_base: controller_websocket - add option to allow session-less WebSocket connections.
mqtt: redo access control checks from external client; don't change topics named like 'site/xyz/foo/bar'
m_identity: allow binary admin username.
core: add m_category:foreach/3 and m_category:fold/4
Update preinstall.rst

Modified note on windows support to be more accurate.
core: added 'no_touch' option with a new m_edge:delete/5.
core: added #media_update_done{} notification.
mod_base: small fixes for async validations. Added optional validations on the form itself, to be run after all other validations pass.
mod_l10n: added 'is_only_known' option, to suppress adding a selected value as an extra option if it is unknown in the list of countries.
This is useful to prevent submit of unknown (or unwanted) country codes.
mod_base: zotonic-1.0js, also pass 'z_submitter' query arg for dynamically added submit buttons.
mod_menu: try to find the editmenu in multiple places. Fixes #690
mod_base: support acl dispatch config options for controller_file_readonly.

Fixes #695.
core: fix "typo" in m_rsc:name_to_id/1.

Introduced by @kaos in commit ac52372f7a54034a993fa6dbf02bf95d09352f8a.
Relates to issue #695.
mod_survey: in printable overview, use fallback to column name when no column caption has been set.
core: fix notify args for #media_update_done.
core: fix medium insert; do not send medium delete notification if nothing is deleted.
mod_admin: remove debug statement.
mod_admin: export menu/1 from m_admin_menu.
mod_base: simplification of livevalidation and 'async' validations.
mod_base/docs: added pickle filter. Fixed confirm doc table.