MacVim registers the mvim url handler to open files and directly jump to lines and columns.
We can use this to convert stacktraces reported by RSpec into clickable mvim-links.
Requires at least MacVim 7.3. To change how MacVim opens external files go to
'Preferences' > 'Open files from applications' and select 'in the current window' and from
the dropdown menu select 'and set the arglist' to open the file in the last active buffer.
Cmd-Click on an mvim-link to open the file.