Merge pull request #24 from geekwright/master

Handful of Cleanups
Handle avatars consitently

No avatar selected is 'blank.gif' in user_avatar.
Use core.userinfo.avatar event to get avatar image URL (which is absolute.)
Alternate avatar module using gravatar.com
Standardize system info block avatar handling

This program uses an array of specific user information rather than a user object, so core.userinfo.avatar listeners modified to also accept array.
Add phpdebugbar ajax support sendDatainHeaders()

 Instead of $xoops->disableErrorReporting(), a program can call $xoops->logger()->quiet() and any loggers which generate output as part of the page will stop the output. In the case of debugbar, the error reporting will continue, but be redirected to the currently displayed debugbar through headers, not page body content.
Merge remote-tracking branch 'upstream/master'