Version bump (1.8.0 - 1.10.0a)

... and small fixings.

Version bump (1.8.0 - 1.9.0a)

- JAR-packaged
- Extension icon.

Upgrade for context menu:
- darker background color for better look,
- visual enhancement for context menu border and for selected menu-items,
- menu separator and arrow are redesigned,
- transparency (now you can enable/disable it),
- rounded corners (now you can enable/disable it).

First release!