WIKI-497 display info message about web pave invalidity when url is incorrect

Fix description:

Problem: This bug occurs only when using iframe macro with wrong param url.
How to fix? : Provide new private method to valid the url of iframe & catch exception when url in iframe is invalid.
WIKI-367: Can not attach file when add link for wiki page
WIKI-367 All Pages tab in Link popup when add rich text wiki page displays wrong
WIKI-367: Can not attach file when add link for wiki page
Fix description:

Un-register xwikiplorer.js in gatein-resoures.xml (unused)
Update the way to requirie xwiki.js and xwikiexplorer.js to make sure that the order of loading
WIKI-435 Wrong position for Restricted tooltip
WIKI-435 Wrong position for Restricted tooltip
WIKI-579:  Wrong position for Restricted tooltip
WIKI-598 handle Exception and Log in WikiImpl.getWikiHome()
WIKI-619 Wiki service return Null page in WikiRestServiceImpl
Problem analysis: WikiRestService.getTreeData using outdated path causes the problem
Solution: Log needed information such as user id, selected path and using wiki homepage instead of outdated one