Fix loading and exclude query issues with authors/roles

[frankiejarrett]

Fixes #527
Fixes #551

/cc @shadyvb Please review

[frankiejarrett]

@shadyvb @lukecarbis Would be great to get one of you to review and test this today. I'd like to get it into the next release, if possible.

[lukecarbis]

Code looks great. I'm still have problems getting Stream to respect my Administrator exclude rule. These screenshots are from multisite, but single site installs have the same issue.

I double checked that I'm an administrator.

I double checked that my exclude rules included the Administrator user role.

Stream still tracks actions that I make.

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I've just done some additional testing, and it seems like it doesn't even respect the user exclude setting (as opposed to the user role, above).

[frankiejarrett]

@lukecarbis OK I found the problem and it's caused by the change introduced in #532 where the priority of connectors loading was set to 9 instead of 10. So the connectors class is loaded before WP_Stream_Settings::$options is even available! Investigating a workaround now...

[frankiejarrett]

@lukecarbis OK, that should do it. Please confirm.

[lukecarbis]

It works!