Update editors/nano to 2.6.0

2016.06.17 - nano 2.6.0 "Rubicon" fixes more than fifty little bugs -- and
some of them not so little.  It improves moving about in
the file browser, corrects failings of the internal spell
checker, adds a new feature (comment/uncomment lines, with
default binding M-3), makes some error messages clearer,
shows more of a file when positionlog is used and the cursor
is near the end, displays all error messages at startup if
there are multiple ones, does not misinterpret keystrokes
when typing very fast, is less eager to trim the filename
on narrow terminals, speeds up case-insensitive searches,
and allows to abort re-searches.  Among bunches of other
things.  It is worth the trouble to upgrade.

(wiedi)