Small improvements in nc app; fixed memleak in zjab; encryption part of zjab was...

Small improvements in nc app; fixed memleak in zjab; encryption part of zjab was moved into separated file
- utils.c; fixed bug in command exec - when TTY was changed and process is closed, previous TTY is not
useable again (frozen), same with netexec; added command top for process's cpu usage; fixed wrong
heap address of usermem mm; fixed problem with TCP/UDP client's port - server don't accept same client's
port more times; fixed wrong character in numerical part of keyboard in czech layout; libc's scanf use
putchar () instead of putch () now; fixed libc's strdup () and strndup () - missing null character