don't use contains in SelectWidget item_query

gives false positive matches when some values are substrings of others
Check for Python errors in js tests

When running a cell in the js tests,
this checks for any errors and treats them as a failure.

Helps avoid confusion caused by silently ignoring failures in Python code.
Use 'is' to compare with None

Issues were detected by PyCharm Community Edition 3.4.
Make sure DOMWidget _css is set after basic style traits
Updating iopubwatcher.py to query for 'text' instead 'data' in the message dict.
Merge pull request #6642 from JIghtuse/master

Use 'is' to compare with None
Merge pull request #6634 from minrk/select-contains

don't use contains in SelectWidget item_query
Merge pull request #6646 from ngoldbaum/iopubfix

Updating iopubwatcher.py to query for 'text' instead 'data' in the message dict
Merge pull request #6637 from minrk/notice-python-error

Check for Python errors in js tests
Merge pull request #6645 from jdfreder/css_order

Make sure DOMWidget _css is set after basic style traits
remove path from external
move pickleshare to external

can remove and make a dependency when pickleshare installs on 3.4 (should be 0.5)
remove decorator from external
remove appnope from external

make it a dependency on OS X
remove pexpect from external

make it a dependency on non-Windows
remove simplegeneric from external

make it a dependency
install ipython[all] with pip

rather than explicit dependency installation