Merge pull request #242 from keepwn/fixs

Fix CellDoubleClickEvent In Winform
Merge pull request #243 from keepwn/fix-dropdown-in-gtk

Fix DropDown In Gtk
Fix registering events when not a default event, which caused GridView in Gtk to not wire events after adding columns.  Fixes #241.
Gtk: Optimize setting up columns/events so that it only happens when loaded. Prevents binding/wiring events each time a column is added/removed.
Mac: When setting ComboBox.Text programatically, it should select the item that matches the text, if any.
Mac: Don't release window when closed. Prevents main window from responding after re-opening.
Add NuGet/MyGet badges

Also updated to shields.io for much nicer build status badge
Wpf: Don't tab stop on SeparatorToolItem when type is space.
Gtk: Ensure menu items are shown when added dynamically, and add test. Fixes #244
Fix potential NRE when closing the form
Merge remote-tracking branch 'kee/develop' into develop