[WiDi API] Fix the issue for the relative url passed to requestShow.

If a relative url is passed to requestShow, the page can not be opened correctly.
Fix it by resolving the url with base url to make it to be an absolute one.
Merge pull request #1163 from kurli/resolve-relative-url

[WiDi API] Fix the issue for the relative url passed to requestShow.
[Android] Implement the native http authentication in xwalk runtime.

  Native http authentication has to be handled in xwalk runtime for Android
port. It is used to provide the xwalk login delegation and handle the http
authentication request. This fix is to provide the native xwalk login delegation
and set up the bridge between the native http authentication handler and corresponding
handler in runtime core java layer.

BUG=https://crosswalk-project.org/jira/browse/XWALK-159