pass c_dir

Now in function startsws, c_dir will be passed.
modify declaration

modify declaration of startsws and clientwrite (include c_dir)
net.c v1.09 (CGI and readdir)

Can hold -c and CGI.
Also list the contents of the directory unless there is a file called
"index.html".
Merge pull request #28 from lzhang25/master

net.c v 1.09(Directory Indexing)