Add missing mappings for named HTML entities (#174)

* Add missing named HTML entity mappings

* Get rid of chained method calls due to compiler resource utilization issues

* Dynamically calculate longest entity name

* Refactor map building to happen in static initializer

* Add comment linking to source data

* Make formatting consistent

* Update Javadoc

* Update Javadoc

* Revert Javadoc changes

* Update decodeEntityAt to return code-units instead of code-points

* Update character literal

* Update list of named character references using official spec

* Simplify long to char conversion

* Refactor decodeEntityAt to appendDecodedEntity

* Remove unused imports

* Add Nullable annotations

* Add unit test to check boundary condition

* Update comment

Author: jshields-squarespace

src/main/java/org/owasp/html/CssTokens.java

@@ -1442,7 +1442,7 @@ private static int[] truncateOrShare(int[] arr, int limit) {
    * See http://dev.w3.org/csswg/css-values/#lengths and
    *     http://dev.w3.org/csswg/css-values/#other-units
    */
-  private static final Trie UNIT_TRIE = new Trie(
+  private static final Trie<Integer> UNIT_TRIE = new Trie<Integer>(
       ImmutableMap.<String, Integer>builder()
         .put("em", LENGTH_UNIT_TYPE)
         .put("ex", LENGTH_UNIT_TYPE)
@@ -1473,7 +1473,7 @@ private static int[] truncateOrShare(int[] arr, int limit) {
 
   static boolean isWellKnownUnit(CharSequence s, int start, int end) {
     if (start == end) { return false; }
-    Trie t = UNIT_TRIE;
+    Trie<Integer> t = UNIT_TRIE;
     for (int i = start; i < end; ++i) {
       char ch = s.charAt(i);
       t = t.lookup('A' <= ch && ch <= 'Z' ? (char) (ch | 32) : ch);

src/main/java/org/owasp/html/Encoding.java

@@ -54,10 +54,8 @@ public static String decodeHtml(String s) {
       int pos = 0;
       int amp = firstAmp;
       while (amp >= 0) {
-        long endAndCodepoint = HtmlEntities.decodeEntityAt(s, amp, n);
-        int end = (int) (endAndCodepoint >>> 32);
-        int codepoint = (int) endAndCodepoint;
-        sb.append(s, pos, amp).appendCodePoint(codepoint);
+        sb.append(s, pos, amp);
+        int end = HtmlEntities.appendDecodedEntity(s, amp, n, sb);
         pos = end;
         amp = s.indexOf('&', end);
       }