Merge pull request #2854 from minrk/2853b Move kernel code into IPython.kernel inprocess Kernel in kernel.inprocess zmq Kernel in kernel.zmq KernelManager stuff and ulities in top-level kernel Main functional change: allow custom kernel Popen command - [x] adds `KernelManager.kernel_cmd` configurable for launching a custom kernel - [x] splits entry_point.base_launch_kernel into two steps: making the launch cmd and launching the subprocess - [x] figure out where the entry_point functions belong, if it should be anywhere else - [x] move IPython.zmq.kernelmanagerabc to IPython.kernel.kernelmanagerabc - [x] move IPython.lib.kernel/IPython/zmq.entry_point to IPython.kernel.launcher / connect - [x] move zmq.ipkernelapp.IPKernelApp to zmq.kernelapp (I'll look at merging the classes, and see if it makes - [x] move IPython.zmq to IPython.kernel.zmq - [x] move IPython.inprocess to IPython.kernel.inprocess - [x] move embed_kernel from zmq.ipkernelapp to zmq.embed - [x] move MultiKernelManager to IPython.kernel.multikernelmanager. - [x] move IPython.zmq.blockingkernelmanager to IPython.kernel.blockingkernelmanager. - [x] move IPython.zmq.kernelmanager to IPython.kernel.kernelmanager. - [x] move IPython.ipkernel.Kernel to IPython.kernel.kernel.