add Integer traitlet

Most int traits are now Integers

Integer differs from Long only in that small `long`s are cast to `int`, rather than
all `int`s being cast to `long`:

    Integer(4L) => 4
    Long(4) => 4L

closes gh-942, closes gh-996.

Rebased to avoid recursive merge for just one commit.

IPython/frontend/html/notebook/kernelmanager.py

@@ -29,7 +29,7 @@ from tornado import web
 from IPython.config.configurable import LoggingConfigurable
 from IPython.zmq.ipkernel import launch_kernel
 from IPython.zmq.kernelmanager import KernelManager
-from IPython.utils.traitlets import Instance, Dict, List, Unicode, Float, Int
+from IPython.utils.traitlets import Instance, Dict, List, Unicode, Float, Integer
 
 #-----------------------------------------------------------------------------
 # Classes
@@ -196,7 +196,7 @@ class MappingKernelManager(MultiKernelManager):
     kernel_argv = List(Unicode)
     kernel_manager = Instance(KernelManager)
     time_to_dead = Float(3.0, config=True, help="""Kernel heartbeat interval in seconds.""")
-    max_msg_size = Int(65536, config=True, help="""
+    max_msg_size = Integer(65536, config=True, help="""
         The max raw message size accepted from the browser
         over a WebSocket connection.
     """)

IPython/frontend/html/notebook/notebookapp.py

@@ -57,7 +57,7 @@ from IPython.zmq.ipkernel import (
     aliases as ipkernel_aliases,
     IPKernelApp
 )
-from IPython.utils.traitlets import Dict, Unicode, Int, List, Enum, Bool
+from IPython.utils.traitlets import Dict, Unicode, Integer, List, Enum, Bool
 
 #-----------------------------------------------------------------------------
 # Module globals
@@ -195,7 +195,7 @@ class NotebookApp(BaseIPythonApplication):
     def _ip_changed(self, name, old, new):
         if new == u'*': self.ip = u''
 
-    port = Int(8888, config=True,
+    port = Integer(8888, config=True,
         help="The port the notebook server will listen on."
     )