Clean up and simplify tmux command argument parsing.
Originally, tmux commands were parsed in the client process into a
struct with the command data which was then serialised and sent to the
server to be executed. The parsing was later moved into the server (an
argv was sent from the client), but the parse step and intermediate
struct was kept.
This change removes that struct and the separate parse step. Argument
parsing and printing is now common to all commands (in arguments.c) with
each command left with just an optional check function (to validate the
arguments at parse time), the exec function and a function to set up any
key bindings (renamed from the old init function).
This is overall more simple and consistent.
There should be no changes to any commands behaviour or syntax although
as this touches every command please watch for any unexpected changes.
Store sessions in an RB tree by name rather than a list, this is tidier
and allows them to easily be shown sorted in various lists
(list-sessions/choose-sessions).
Keep a session index which is used in a couple of places internally but
make it an ever-increasing number rather than filling in gaps with new
sessions.
Add "grouped sessions" which have independent name, options, current window and
so on but where the linked windows are synchronized (ie creating, killing
windows and so on are mirrored between the sessions). A grouped session may be
created by passing -t to new-session.
Had this around for a while, tested by a couple of people.
Add a choose-client command and extend choose-{session,window} to accept a
template. After a choice is made, %% (or %1) in the template is replaced by the
name of the session, window or client suitable for -t and the result executed
as a command. So, for example, "choose-window "killw -t '%%'"" will kill the
selected window.
The defaults if no template is given are (as now) select-window for
choose-window, switch-client for choose-session, and detach-client for
choose-client (now bound to D).
Make all messages sent between the client and server fixed size.
This is the first of two changes to make the protocol more resilient and less
sensitive to other changes in the code, particularly with commands. The client
now packs argv into a buffer and sends it to the server for parsing, rather
than doing it itself and sending the parsed command data.
As a side-effect this also removes a lot of now-unused command marshalling
code.
Mixing a server without this change and a client with or vice versa will cause
tmux to hang or crash, please ensure that tmux is entirely killed before
upgrading.
maintain and is only going to get worse as more are used. So instead, add a new
uint64_t member to cmd_entry which is a bitmask of upper and lowercase options
accepted by the command.
This means new single character options can be used without the need to add it
explicitly to the list.
