Add plugin/theme author/contributor badges

[coffee2code]

The forums under bbPress 1 displayed badges to users who were authors or contributors to a given plugin or theme for their replies within their own plugin/theme support forums. This functionality should be reimplemented for bbPress 2.

More specifically, these were the badge criteria that were in place:

• When in a plugin- or theme-related forum topic (for support forums and reviews), add a badge to a contributor's reply if they are associated with the related plugin/theme.
• Badge appeared as white text on a green background in the user info section of each reply, when applicable.
• "Plugin Author" badge is shown if the replying user has commit access to the plugin.
• "Plugin Contributor" badge is shown if the replying user is listed as a contributor to the plugin (but does not have commit access).
• "Theme Author" badge is shown if the replying user is the author of the theme.
• Themes do no currently support additional contributors (see #27) so there is no "Theme Contributor" badge.

[coffee2code]

Display of "Plugin Author" badge under bbPress 2

[coffee2code]

Attached a screenshot of what the badge will look like under bbPress 2. It is likely to change (especially with a new forums theme in the works), but it should be serviceable for now.

[coffee2code]

In 3977:

Support: User Badges initial folder commit.

See #1993.

[coffee2code]

In 3978:

Support: User Badges initial commit.

Adds badges to user replies. Currently assigns one of three potential badges:

• Plugin Author : replies made in the support/review forum for a plugin the reply author has commit access to
• Plugin Contributor : replies made in the support/review forum for a plugin the reply author is listed as a contributor
• Theme Author : replies made in the support/review forum for a theme the reply author has commit access to

See #1544.
Fixes #1993.

[coffee2code]

In 3979:

Forums Theme: Add styles for plugin/theme author/contributor user badges.

See #1993.