pass -no-undefined to libtool on Cygwin for building shlib.
Not all linux systems will have netstat(8), but if they don't then they'll
have ss(8) which does the same thing.
(With out netstat the build stalls in an endless for loop.)

So add a hack that creates a tool named netstat from ss.
Enable usage of gcc-4.8 as PKGSRC_COMPILER
Add MKDIR_P to the configure env.
Remove stray space from the DEPENDS line, fixes dependency problems.