CB-5346 Fix and cleanup broken Android unit test

- Found stale cordova.js in the test project. Changed ant script to copy in
  a fresh one in the pre-build stage. Removed stale copies from git, added
  to .gitignore. This is what was causing the test failure when sending
  javascript to the webview.
- Found almost-stale copy of device plugin, did the same as above.
- Fixed spacing in log messages in CordovaWebView.
- Updated README.md with current information.
- Removed dollar signs that were previously accidently appended to the license.
- Added cordova version to html pages, next to the other metadata.
- Fix incorrect separator in the viewport meta tag.
- Changed old-style <log> tag to <preference name="loglevel"> in config.xml.
- In BackButtonMultiPageTest, increased the TIMEOUT so the deviceready event
  can trigger the referenced javascript, improved the setup() method to
  explicitly load the starting point.

test/res/xml/config.xml

@@ -9,7 +9,7 @@
     </author>
     <access origin="*.apache.org" />
     <content src="index.html" />
-    <log level="DEBUG" />
+    <preference name="loglevel" value="DEBUG" />
     <preference name="useBrowserHistory" value="true" />
     <preference name="exit-on-suspend" value="false" />
     <feature name="Activity">