1. A memory corruption issue that occurs from a paste operation that would overflow the fixed buffer size for keyboard processing.
2. A stall in getch() processing when there are cached keycodes in the termcurses emulation (tcurses_vt100.c).
- fix error "sz_main.o: No such file or directory"
- support -p <path> for rz to change the folder for the recevied file
- switch debug output from printf to syslog
- send the next packet for ZME_ACK in ZMS_SENDING to avoid rz on the host side stuck
- make send work reliable even without hardware flow control
