manpage: document shift+pgup/pgdwn bindings
input: fix autorepeat

Mismatching units in timeout calculation.

Also, as a near-cosmetic change, explicitly wake up the core on the
right time. Currently this does nothing, because the core is woken up
anyway - but it will matter with the next commit.
input: simplify

Just some minor things. In particular, don't call mp_input_wakeup()
manually, but make it part of queuing commands (as far as possible).
input: don't autorepeat cycle_values command

Not sure why this was originally added as autorepeated. It makes no
sense, because switching between choices should never autorepeat. (For
the normal "add"/"cycle" commands, autorepeat is usually enabled, but
command.c tries to disable it specifically for choice properties.)
player: fix idle mode event handling

Idle mode went to sleep too early, e.g. just pressing "ESC" did nothing,
until the next event happened. This was because it directly went to
sleep after processing commands. What we should do instead is rechecking
all state after processing commands, redraw OSD, and then go to sleep.
This also fixes some strange OSD-related behavior.

Also move some other code around to separate idle mode initialization
from the normal run loop.
m_config: fix theoretic undefined behavior

The memcpy() is actually not enough: the types are incompatible, and no
memcpy, union, etc. will change that. (Although no real compiler will
ever break this.) Attempt to make this theoretically correct by actually
using a struct pointer. It's not the same struct type, but supposedly
it's ok, because all struct pointers always have the same size and
representation in standard C.