makeTestData flexed, sprintf to snprintf, inet_addr to inet_pton

everywhere:
- sprintfs changed to snprintf
- strcats changed to strncat
- a few more globals prepended with g_

makeTestData.py:
- allow passing of args or file to make the data

files.cpp:
- generate_base_path takes a length for the string passed in (for
snprintf)
- removed redundant debug_print (print_bytes does the same thing)

udpipe_server.cpp:
- changed from using inet_addr to forward handling inet_pton instead