Don't reset the readline completer after each prompt

This makes it impossible to setup a custom completer. The comment says that
"we must ensure that our completer is back in place," but I don't see why. All
that does it make it impossible to use a different completer. One can trick
IPython into not doing this by monkeypatching ip.has_readline to False, but
then certain features like multiline editing are no longer enabled.

See https://github.com/davidhalter/jedi/pull/321.
Use svg by default due to lack of Ghostscript by default on Windows
add utils.darwin.disable_app_nap

disables the App Nap energy saving behavior of OS X 10.9.
Requires PyObjC, which is included in System Python,
but not in many other Python installations.

It is pip-installable, but takes ages to compile.

should close #4431
add appnope to external
use QSocketNotifier, not poll

avoids having to disable App Nap outright.

Also use appnope context manager to disable App Nap on OS X 10.9 while processing events.

Adds IPKernel._darwin_app_nap flag, so that working with App Nap can be disabled, in case appnope causes problems for some.

App Nap is just disabled outright on wx.
relax ipconfig matching on Windows

looser match via regular expression, doesn't make English assumptions.
don't include 127.0.0.1 in load_ips_ipconfig
add utils.pickleutil.use_dill

enables dill extended serialization support
add DirectView.use_dill
add parallel dill example
add use_dill note to what's new
change how dill is enabled

set mod.pickle = dill
move raw cell inclusion to null.tpl

select based on raw_format metadata key if defined.
Default behavior is to include raw cells of unspecified format (consistent with existing behavior).
add raw_format to Exporter classes

sets their values in resources
test raw cell inclusion based on raw_format metadata
rename Raw Text to Raw NBConvert in menu
tweak global hide/show

make hierarchical rather than either/or.  Also, don't use the same class name for the outer and inner css classes.
give Raw Cells a placeholder

and make sure cell_type is defined *before* calling TextCell.apply
clarify name of 'default' cell toolbar
allow cell toolbar presets to apply only to specific cell types