server limits commands to MAX_CMD_LEN

[Szabolcs Nagy]

some of my long ssh commands failed with

exec request failed on channel 0

and it seems the dropbear server rejected them because of the limits
in sysoptions.h:

#define MAX_CMD_LEN 1024 /* max length of a command */
//...
#define MAX_STRING_LEN 2400 /* Sun SSH needs this long for algos */

i assume these affect scp too, so i think it would make sense
if they were at least the historical PATH_MAX (4K).

(MAX_CMD_LEN is probably not needed if MAX_STRING_LEN already
limits the command buffer size).

or am i expected to manually tweak these limits if i want
to run commands using long filenames?

thanks