cmd/webspin: add simple web server for serving content from upspin
cmd/webspin: add simple web server for serving content from upspin

Not ready for any kind of production use.

Change-Id: Id435eb06b057457d32fb87ad18776e2e6bcb463c
Reviewed-on: https://upspin-review.git.corp.google.com/2251
Reviewed-by: Rob Pike <4dc7c9ec434ed06502767136789763ec11d2c4b7@google.com>
Reviewed-by: Eduardo Pinheiro <55040cbb39ba395339ae7940d8da6cd97797a4a8@google.com>

upspin/upspin,upspin/upspin