Validate initial value of "_BoundedFloatWidget".
Add failing test for issue gh-6009
Use shell futures environment for code in %time and %timeit

Closes gh-6009
add kernelspec completions
fix nicer ImportError message on Python 3

Exception.message is not defined on Python 3
insert -h --help and --help-all completion options
fix locate profile completion
added install-nbextension and trust completions
demote "iopub lacks parent" to debug-level

these happen all the time, and aren’t worth warning about
Merge pull request #6016 from minrk/fix-nice-not-so-much

fix nicer ImportError message on Python 3
Merge pull request #6021 from minrk/debug-lacks-parent

demote "iopub lacks parent" message to debug-level
Make tab completion for 'from' suggest symlinked folders/modules.
Add failing test for gh-6025
Only allow '>>>' prompt without space afterwards if line is blank

Closes gh-6025
Merge pull request #6024 from cxmcc/tab-completion-for-symlink-folders

Make tab completion for 'from' suggest symlinked folders/modules.
Merge pull request #6027 from takluyver/i6025

Only allow >>> prompt without space afterwards if line is blank
Merge pull request #6017 from ivanov/moar-completions

kernelspec completions
Merge pull request #6010 from takluyver/i6009

Use shell futures environment for code in %time and %timeit
Merge pull request #6000 from AlbertHilb/FloatWidgetValueFix

Validate initial value of "_BoundedFloatWidget".
Fix typo in docs