Improve image diffs

This is a GitBlit 1.7.0 preview: essentially

* gitblit-org/gitblit#229
* gitblit-org/gitblit#230
* gitblit-org/gitblit#231
* gitblit-org/gitblit#232

Replace the CSS-based slider by a JavaScript-based one, plus blink
comparator, plus pixel difference on browsers that support it.

Author: tomaswolf

pom.xml

@@ -20,7 +20,7 @@ limitations under the License.
   <artifactId>gitblit-plugin</artifactId>
   <description>GitBlit for Gerrit integrated as a plugin</description>
   <name>Gerrit - GitBlit Plugin</name>
-  <version>2.9.1.162.1-SNAPSHOT</version><!-- Gerrit API version followed by collapsed GitBlit version, followed by plugin version -->
+  <version>2.9.1.162.2-SNAPSHOT</version><!-- Gerrit API version followed by collapsed GitBlit version, followed by plugin version -->
   <licenses>
     <license>
       <name>Apache License 2.0</name>
@@ -223,16 +223,20 @@ limitations under the License.
                       We replace some parts of GitBlit related to tits diff display. This fixes GitBlit issue 450,
                       and also adds improved image diff capabilities.
                      -->
-                    <exclude>com/gitblit/utils/GitBlitDiffFormatter.class</exclude>
+                    <exclude>com/gitblit/utils/GitBlitDiffFormatter.class</exclude> <!-- Diff improvements -->
                     <exclude>com/gitblit/utils/DiffUtils.class</exclude>
                     <exclude>com/gitblit/utils/DiffUtils$*.class</exclude>
-                    <exclude>com/gitblit/wicket/pages/CommitDiffPage.class</exclude>
+                    <exclude>com/gitblit/wicket/pages/BasePage.class</exclude><!--  Support for bottom scripts -->
+                    <exclude>com/gitblit/wicket/pages/BasePage$*.class</exclude>
+                    <exclude>com/gitblit/wicket/pages/BlobPage.class</exclude><!--  Bug fix -->
+                    <exclude>com/gitblit/wicket/pages/BlobPage$*.class</exclude>
+                    <exclude>com/gitblit/wicket/pages/CommitDiffPage.class</exclude><!-- Diff improvements -->
                     <exclude>com/gitblit/wicket/pages/CommitDiffPage$*.class</exclude>
                     <exclude>com/gitblit/wicket/pages/ComparePage.class</exclude>
                     <exclude>com/gitblit/wicket/pages/ComparePage$*.class</exclude>
                     <exclude>com/gitblit/wicket/pages/BlobDiffPage.class</exclude>
                     <exclude>com/gitblit/wicket/pages/BlobDiffPage$*.class</exclude>
-                    <exclude>gitblit.css</exclude>
+                    <exclude>gitblit.css</exclude><!-- Diff improvements -->
                   </excludes>
                 </filter>
                 <filter>

src/main/java/com/gitblit/utils/GitBlitDiffFormatter.java

@@ -143,7 +143,7 @@ public void write(byte[] b, int offset, int length) {
 			if (binaryDiffHandler != null && RawParseUtils.decode(Arrays.copyOfRange(b, offset, offset + length)).contains(BINARY_DIFFERENCE)) {
 				String binaryDiff = binaryDiffHandler.renderBinaryDiff(formatter.entry);
 				if (binaryDiff != null) {
-					byte[] bb = ("<tr><td colspan='4'>" + binaryDiff + "</td></tr>").getBytes(StandardCharsets.UTF_8);
+					byte[] bb = ("<tr><td colspan='4' align='center'>" + binaryDiff + "</td></tr>").getBytes(StandardCharsets.UTF_8);
 					super.write(bb, 0, bb.length);
 					return;
 				}