Referencing $(srcdir) in the gemspec is not really an option, as "gem build"
includes the full path in the gem, so we need to build in $(srcdir). As there
does not seem to be a way to control the output of "gem build", we manually
move the gem to $(builddir) in OOT builds.
As the underlying C functions, send/recv on ruby sockets are not guaranteed
to send/recv all requested bytes. Use wrapper functions to make sure we get
all bytes needed.
Martin Willi