These are now equivalent to combining commands with the "cycle pause" or
"set pause" commands, and thus are not needed anymore. They were also
obscure and undocumented.
This was broken by commit bb6b543812. Note that the original pull
request was fine, but it was broken by my own stupidity when I was
"improving" it.
The problem is that the new loadfile argument was not considered
optional anymore after my changes. The original pull request did handle
this by setting .defval to a dummy value, but I removed that part.
Fix it again by introducing a flag that designates that the parameter is
optional. (I didn't want to add it to m_option.h, because technically,
all options are optional, and it's not possible to have non-optional
options.)
Until now, strings were the only allowed dynamically allocated argument
type in input commands. Extend it so that it works for any type. (The
string expansion in command.c is of course still string specific.)
This code is shared between input.conf parser and option parser. Until
now, the performance didn't really matter. But I want to use this code
for JSON parsing too, and since JSON will have to be parsed a lot, it
should probably try to avoid realloc'ing too much.
This commit moves parsing of C-style escaped strings into a common
function, and allows using it in a way realloc can be completely
avoided, if the already allocated buffer is large enough.
