godoc: provide mode for flat (non-indented) directory listings
This feature should make it easier to look at very large
directory trees.
- a new mode (URL: /pkg/?m=flat) shows directory listings w/o
indentation and entries with full path (html and text mode)
- in text mode, hierarchical (non-flat) directory listings are
now presented with indentation (/pkg/?m=text)
- in html mode, hierarchical (non-flat) directory listings are
presented with slightly less indentation
- there is an internal hook for programmatic control of the
display mode (for specialized versions of godoc).
R=bradfitz
CC=golang-dev, rsc
https://golang.org/cl/
5410043