cmdutil: use crecordmod.checkcurses stable

cmdutil: use crecordmod.checkcurses

Instead of blindly trusting the user's experimental.crecord, we use checkcurses
to abstract that logic so that we can handle the case where python was not
built with curses.

--- a/mercurial/cmdutil.py	Tue Dec 15 16:00:06 2015 -0800
+++ b/mercurial/cmdutil.py	Tue Dec 15 16:01:45 2015 -0800
@@ -66,7 +66,7 @@
     what kind of filtering they are doing: reverting, committing, shelving, etc.
     *operation* has to be a translated string.
     """
-    usecurses =  ui.configbool('experimental', 'crecord', False)
+    usecurses = crecordmod.checkcurses(ui)
     testfile = ui.config('experimental', 'crecordtest', None)
     oldwrite = setupwrapcolorwrite(ui)
     try: