Prevented the error message "*** Error 1 (ignored) ***" during installation
by using || instead of &&.
Shell commands are hidden during normal operation.
Go packages can be tested using "bmake test".
ok @bsiegert
Go packages now define a set of files to buildlink in their buildlink3.mk.
go-packages.mk no longer looks in ${PREFIX}/gopkg during the build. This
should also fix the spurious issues with rebuilds of .a files during bulk
builds of Go packages.