The Set type is gone. Instead, templates are automatically associated by
being parsed together; nested definitions implicitly create associations.
Only associated templates can invoke one another.
This approach dramatically reduces the breadth of the construction API.
For now, html/template is deleted from src/pkg/Makefile, so this can
be checked in. Nothing in the tree depends on it. It will be updated next.
R=dsymonds, adg, rsc, r, gri, mikesamuel, nigeltao
CC=golang-dev
https://golang.org/cl/5415060
No longer do we generate HTML from it; instead the input
file is already in HTML but has template invocations to
extract programs from other files.
Delete htmlgen, which is no longer needed.
Add tmpltohtml, which runs the templating code.
R=golang-dev, dsymonds, adg
CC=golang-dev
https://golang.org/cl/4699041
