Fix non-libtool build on Ubuntu...
Fix non-libtool build on Ubuntu...

Yet again, in their quest to be different for no apparent reason, Ubuntu
have added "--as-needed" to their default ld flags. This leads to
incomplete linkage for Lua modules that link to other libraries, unless
it's manually set back to the (very sensible) default.

craigbarnes/lua-gumbo,craigbarnes/lua-gumbo,craigbarnes/lua-gumbo