In addition of $EDITOR, support $VISUAL too

[tuju]

man less

       v      Invokes an editor to edit the current file being viewed. The editor 
              is taken from the  environment variable VISUAL if defined, or EDITOR
              if VISUAL is not defined, or defaults to "vi" if neither VISUAL nor
              EDITOR is defined.

I wouldn't be surprised that it's been defined in some POSIX specs, but regardless of that, we could support old farts using the $VISUAL too. :)

[bricks]

Should we switch EDITOR and VISUAL?

#ifdef _WIN32
	editcmd = g_strdup_printf("notepad %s", tmpfile);
#else
	if (!(editor = getenv("EDITOR")))
		editor = getenv("VISUAL");
	
	if (editor)
		editcmd = g_strdup_printf("%s %s", editor, tmpfile);
	else	
		editcmd = g_strdup_printf("vi %s", tmpfile);
#endif

[tuju]

Didn't find POSIX definition for this, but many other sources claim VISUAL over EDITOR like:

​http://www.mkssoftware.com/docs/man1/sh.1.asp#ENVIRONMENT_VARIABLES ​http://seejeffrun.blogspot.com/2008/07/setting-defaults-properly.html

and when failing on those, then trying to launch vi.

[dgollub]

I don't care - feel free to switch this. This should not block any release.

[felixmoeller]

I committed this with r382 of msynctool.