At the moment, building WeeChat triggers several thousand -Wstrict-prototypes
diagnostics. This is due to its source code using an empty argument list for
functions and function pointers that take no arguments, instead of explicitly
declaring that they take no arguments by using a void list.
This commit replaces all empty argument lists with a void list.
Note that Ruby's headers also suffer the same problem, which WeeChat can't
do anything to fix. Thus, building WeeChat with the Ruby plugin enabled
will still issue approximately 30 such diagnostics.
The id is a "long long" variable with the current time (microseconds
precision).
It is guaranteed to be unique for all groups and nicks inside the buffer, and
the same number is never used again in the same buffer, during the lifetime of
the process.
It persists and is unchanged after `/upgrade`.
Sébastien Helleu