mouse-right for opening a link dialog removed. Refs: #175.
No longer different behavior depending on text mode.
Ctrl + mouse left -> reveal link cmd inside text, unless read-only.
Ctrl + mouse right -> open link dialog.
Plus an off-by-one error fixed in isHot for the right-sided link view.
Docu updated accordingly.

Signed-off-by: Josef Templ <josef.templ@gmail.com>