add alt-n commands to (replace|append) previous match

Note: alt-n command were used to replace main selection with next match
      (preserving the others)
Merge remote-tracking branch 'alexherbo2/previous-match'
Remove 'ReplaceMain' select mode
NCurses: change scroll bar characters
add rc/json.kak
string and comment do not require white space before
single string is not escapable
minor style fix
add rc/python.kak
add rc/ruby.kak
add rc/yaml.kak
Use colors in status bar for certain flags
Fix redrawing of windows when only the status line changes
Do not write '*** kak: fifo closed ***' in buffers

The status line '[fifo]' flag should replace that
Merge various language support scripts
Merge remote-tracking branch 'alexherbo2/json-rc'
Fix :map scope completion
fix single line comments highlighting
highlight multi-line comments