Second release of rig-remote

Hello,

Welcome to the second release of rig-remote. The major improvements, among all the little things are:

threading and events support for all the scanning commands
tooltips in the UI
selection/deselection of bookmarks in the bookmark lists is now available
increased the testing coverage in all the modules, improved code readability
long list of small fixes and corrections.
The list of issues related to this release is here https://goo.gl/e3P1MM

Enjoy.