Also switch usage printing to using stderr always, as is common for Go
tools.
Change-Id: I240da4344fe6b51a418c0d4b0b7d7e7d5614c1d7
Reviewed-on: https://go-review.googlesource.com/129776
Reviewed-by: Alan Donovan <adonovan@google.com>
Such messages are more informative when the error occurs deep within a script.
Also: add tool name to digraph's usage messages.
LGTM=gri
R=gri
CC=golang-codereviews
https://golang.org/cl/173380043
Rewrite performed with this command:
sed -i '' 's_code.google.com/p/go\._golang.org/x/_g' \
$(grep -lr 'code.google.com/p/go.' *)
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/170920043
Example: show the transitive closure of imports of the digraph tool itself:
% go list -f '{{.ImportPath}}{{.Imports}}' ... | tr '[]' ' ' |
digraph forward code.google.com/p/go.tools/cmd/digraph
+ basic test.
LGTM=gri
R=gri, sameer
CC=golang-codereviews
https://golang.org/cl/161760043
