[COMMANDS] cmd_profile: usr strlcpy instead of strcpy

Signed-off-by: Jean-Christophe DUBOIS <jcd@tribudubois.net>
[LIBS] stringlib: move to POSIX conversion functions.

There is also a rewrite of most string related functions

Signed-off-by: Jean-Christophe DUBOIS <jcd@tribudubois.net>