Changed perror to fprintf for consistancy of error messaging

+ Also closing the listensock at every failure, rather than just a few
Removing unnecessary sendall, my sends are blocking, so unless they go
out they're either wait or die. Waiting is not ideal; I may return to
make these non-blocking sockets later.
Added a strings utilities header and source file

+ I needed a function that will look for the first-occurance of a
character given a string length, which is not something that is
available in string.h
Moving parsing out of readall and into its own function

+ readall() handles, albeit sloppy, the telnet EOL and sends a buffer up
to the EOL (right now, for testing, just looks for \r) to be parsed
Merge branch 'dev' of bitbucket.org:marsol0x/chatserver into dev