fix #564, fix #652 - improve handling of mouse-driven selections

- Clicking in visual mode/normal leaves user in normal mode.
- Shift-clicking enters visual mode.
- In both cases, xpos is updated.
add command palette command to open/create .vintageousrc
reload settings after resetting state via command palette
Merge pull request #660 from my-personal-forks/mouse-handling

fix #564, fix #652 - improve handling of mouse-driven selections
Merge pull request #661 from my-personal-forks/vintageous-command

add command palette command to open/create .vintageousrc
Merge pull request #662 from my-personal-forks/improve-reset

reload settings after resetting state via command palette