2. make the libcurl and curl version the same

  input
o have ->passwd and ->name be NULL if no name/passwd was given
o only set default user+password for FTP if no userpwd was given

#include "../lib/memdebug.h" for memory debug builds.

command line.

hogs Windows machines when libcurl is being used multi-threaded (with > ~50
threads). Andrew Fuller helped us verify and test this.

According to a MSDN web page on connect(), it returns 0 when the connect
is done and thus we don't need the getsockopt() call anyway on Windows.