Revert "Use ESLint instead of JSHint"

This reverts commit d7ecb98.
Seems like the version of Node.js preinstalled in our Travis images
is too old for this version of ESLint,
and this is not interesting enough for me to investigate/fix.

.travis.yml

@@ -23,7 +23,7 @@ install:
     - pip install -e .
     - pip install -r tools/requirements.txt
     - tools/vnu.sh install
-    - tools/eslint.sh install
+    - tools/jshint.sh install
 
 cache: pip
 
@@ -40,7 +40,7 @@ script:
     # This includes validating an actual HTML report (``showcase.html``).
     - tools/vnu.sh run extra_doc/_build/*.html
     - tools/css_validator.sh httpolice/reports/html.css
-    - tools/eslint.sh run httpolice/reports/html.js
+    - tools/jshint.sh run httpolice/reports/html.js
 
     # Although the main docs (``doc/``) are processed by Read the Docs,
     # we still want to check that they are building OK.

httpolice/reports/html.js

@@ -1,3 +1,6 @@
+/* jshint browser: true */
+/* jshint -W097 */
+
 'use strict';
 
 function collapseAll() {
@@ -8,6 +11,7 @@ function collapseAll() {
 }
 
 function onButtonClick() {
+    /* jshint -W040 */
     this.parentElement.classList.toggle('collapsed');
 }
 
@@ -23,6 +27,7 @@ function installButtons() {
 }
 
 function highlightReferences() {
+    /* jshint -W040 */
     var i, referrers, refs, exchange, target;
 
     // Collect references from all contributing elements within this notice.

tools/eslint.sh → tools/jshint.sh

@@ -2,8 +2,8 @@
 
 set -e
 
-VERSION=3.2.2
-BASE=$HOME/install-eslint
+VERSION=2.9.2
+BASE=$HOME/install-jshint
 
 action=$1
 shift
@@ -13,10 +13,10 @@ case $action in
         rm -rf "$BASE"
         mkdir "$BASE"
         cd "$BASE"
-        npm install eslint@$VERSION
+        npm install jshint@$VERSION
         ;;
 
     run)
-        "$BASE/node_modules/.bin/eslint" "$@"
+        "$BASE/node_modules/.bin/jshint" "$@"
         ;;
 esac