ControlZ should suspend IPython to the background.

IPython/terminal/ptshell.py

@@ -3,6 +3,7 b' from __future__ import print_function'
 
 import os
 import sys
+import signal
 
 from IPython.core.interactiveshell import InteractiveShell
 from IPython.utils.py3compat import PY3, cast_unicode_py2, input
@@ -136,6 +137,12 b' class TerminalInteractiveShell(InteractiveShell):'
         def _(event):
             event.current_buffer.reset()
 
+        supports_suspend = Condition(lambda cli: hasattr(signal, 'SIGTSTP'))
+
+        @kbmanager.registry.add_binding(Keys.ControlZ, filter=supports_suspend)
+        def _(event):
+            event.cli.suspend_to_background()
+
         @Condition
         def cursor_in_leading_ws(cli):
             before = cli.application.buffer.document.current_line_before_cursor