emit event when mimetype are append to output area.
fix Brian and Min comment
Fixme comment + whatsnew
reorder class properties
make paste focuses the pasted cell

This is to make paste behave in the same manner that insert cell above
and below currently work (inserting a new item causes that item to
receive focus).

This solves a problem where, if a user pastes below a cell whose bottom
edge is below the current viewing area, they have no indication that any
action has occurred. The same applies for paste above a cell whose top
edge is occluded.
put OutputArea map at the end
Add failing test for pretty repr of super() objects
Fix pretty reprs of super objects
Make `SelectionWidget.values` a dict

rename 'labels' and '_value' to 'value_names' and 'value_name'.

To specify a mapping of value names and values, use a dict.
If you specify `values=[list]`, then an OrderedDict will be used.

Assignment after construction only supports a dict.
value_names is read-only
mention that pexpect ships in IPython.external

and only check for it on posix
only put Python major version in wheel tags

results in 'py2-none-any' instead of 'py27-none-any'.

This is supported by pip and PEP 425, but not available from bdist_wheel by default.
exclude notebook checkpoints from manifest
platform-dependent requirements

in bdist_wheel
always construct requirements
whitelist installed components

we don't need most of what's in components to be installed.
Much of it is included just for sdists or development.
we only install man pages to usr/share

let the function reflect this, rather than having several entries with no files.
only check for dependencies when installing without setuptools
fix missing-wheel command

because an empty distutils command must implement three no-op methods and one class attribute.

Which makes perfect sense.
validate package_data

and fix errors caught by the validation