Add "New Tab" Option in Menu of Dock Icon

[xziya]

It's a little inconvenient when closing all the tabs and want to open a new one. Shall we add "New Tab" Option in the dock menu? Or just create a new tab when click the dock icon?

[dteoh]

In v0.7.0, clicking on the dock icon will open a new window if there is none.

[xziya]

Thanks a lot.