proxychains-ng Fix 256 and more

This fixes issue #256 and another issue where calling the proxychains4 binary with a relative path can cause some child processes to fail to load the library under certain conditions. This can happen when not using the wrapper too if the value of the envvar is not an absolute path. I don't fix that issue because I didn't want to write the code to potentially need to search through a list of paths to find our library and make it absolute. The caller should know to make the path absolute.

There is also an update to PDEBUG to always output the PID in a prefix. This is helpful for multi-process applications.

Sep 01 '18 10:09 crass

welcome back! i made some comment, apart from that it looks good

Sep 01 '18 14:09 rofl0r

Hey and thanks! I changed the strncpy to snprintf, but I'm not seeing why it was problematic (there was an issue where the len param should've been sizeof(pbuf)-1). Can you give me clue? And good catch on the debug.h issue, that was entirely unintentional.

Sep 03 '18 02:09 crass

@crass did you see my response re: strncpy() ? seems i was waiting for feedback and then forgot about the PR. is everything resolved now from your PoV ?

Dec 02 '18 13:12 rofl0r