native callfunc_begin_i(func, plugin = -1);
Plugin filename, if empty the calling plugin is targeted
The filename has to be the full exact name (e.g. stats.amxx)
Initiates a function call to this or another plugin by function id.
This only sets up the function call and covers the pre-requisites.
Push parameters using the callfunc_push_* set of functions. The call
will be executed only upon using callfunc_end()
The function id can be retrieved by get_func_id()
1 on success
-1 if plugin was not found
-2 if function is not executable
If called while another callfunc has not yet been finished,
or the specified function is invalid, an error is thrown.