More updates for WordPress.org Theme Approval

functions.php
- Enqueued Google Fonts

header.php
- Removed Google Fonts

style.css
- Changed Template name to just 'p2'
- Added required license and tags
- Added styles for display of P2 recent comments avatars
- Misc cleanup and bug fixes

Removed screenshot.jpg, replaced with screenshot.png

Signed-off-by: Ryan <ryan@ryansommers.com>