Meta: fix and prevent Bikeshed warnings

* Make builds fail on Bikeshed warnings, and display them, instead of silently proceeding.
* Remove duplicate w3c_process_revision ID to work around speced/bikeshed#1503.
* Depend on Infra explicitly to get some conformance stuff, instead of saying it again here. This removes the un-exported "processing equivalence" definition.

Closes #492.

Author: domenic

Makefile

@@ -1,3 +1,5 @@
+SHELL=/bin/bash
+
 bs_installed  := $(shell command -v bikeshed 2> /dev/null)
 npm_installed := $(shell command -v npm 2> /dev/null)
 pp_webidl_installed := $(shell npm ls webidl-grammar-post-processor --parseable --depth=0 2> /dev/null)
@@ -6,15 +8,25 @@ all : index.html
 
 index.html : index.bs
 ifdef bs_installed
-	bikeshed spec index.bs
+	bikeshed spec --die-on=warning index.bs
 else
 	@echo Can\'t find a local version of Bikeshed. To install it, visit:
 	@echo
 	@echo https://github.com/tabatkins/bikeshed/blob/master/docs/install.md
 	@echo
 	@echo Trying to build the spec using the online API at: https://api.csswg.org/bikeshed/
 	@echo This will fail if you are not connected to the network.
-	curl https://api.csswg.org/bikeshed/ -F [email protected] > index.html
+	@ (HTTP_STATUS=$$(curl https://api.csswg.org/bikeshed/ \
+	                       --output index.html \
+	                       --write-out "%{http_code}" \
+	                       --header "Accept: text/plain, text/html" \
+	                       -F die-on=warning \
+	                       -F [email protected]) && \
+	[[ "$$HTTP_STATUS" -eq "200" ]]) || ( \
+		echo ""; cat index.html; echo ""; \
+		rm -f index.html; \
+		exit 22 \
+	);
 endif
 ifdef pp_webidl_installed
 	npm run pp-webidl -- --input index.html

index.bs

@@ -423,7 +423,7 @@ urlPrefix: https://tc39.github.io/ecma262/; spec: ECMA-262
 
 <p>
     This document is governed by the
-    <a id="w3c_process_revision" href="https://www.w3.org/2017/Process-20170301/">1 March 2017
+    <a href="https://www.w3.org/2017/Process-20170301/">1 March 2017
     <abbr title="World Wide Web Consortium">W3C</abbr> Process Document</a>.
 
 <p>
@@ -14635,31 +14635,7 @@ The following conventions are used in the algorithms in this document:
 Everything in this specification is normative except for diagrams,
 examples, notes and sections marked as being informative.
 
-The keywords “must”,
-“must not”,
-“required”,
-“shall”,
-“shall not”,
-“should”,
-“should not”,
-“recommended”,
-“may” and
-“optional” in this document are to be
-interpreted as described in
-<cite><a href="http://tools.ietf.org/html/rfc2119">Key words for use in RFCs to
-Indicate Requirement Levels</a></cite>
-[[!RFC2119]].
-
-Requirements phrased in the imperative as part of algorithms (such as
-“strip any leading space characters” or “return false and abort these
-steps”) are to be interpreted with the meaning of the key word (“must”,
-“should”, “may”, etc) used in introducing the algorithm.
-
-Conformance requirements phrased as algorithms or specific steps can be
-implemented in any manner, so long as the end result is <dfn lt="processing equivalence" id="dfn-processing-equivalence">equivalent</dfn>. In
-particular, the algorithms defined in this specification are intended to
-be easy to understand and are not intended to be performant. Implementers
-are encouraged to optimize.
+This specification depends on the Infra Standard. [[!INFRA]]
 
 The following conformance classes are defined by this specification: