Generate docs for config options.
Remove outdated config information
Start separating config docs into user and developer parts
Remove superfluous info on config system
Fix cross references from 0.11 whatsnew
Move editor config info into details.rst
Merge branch 'doc-config-options' into docs-refresh

Conflicts:
	docs/source/config/index.rst
Refer to options list in config intro
Rearrange index page of config docs
CSS tweaks to make definition lists look nicer
Fix width of search box
Refer to how to set config from options list
Fix some Sphinx warnings with autogenerated config docs
Describe CL precedence over config files
Mention that some options cannot be set through %config
don't extract dates in metadata or content

protects user-defined strings from being deserialized to datetime objects
fix ISO8601 re

closes #4493
apply extract_dates at a higher level in IPython.parallel

datetime objects are no longer automatically deserialized outside of headers.
separate single-date parsing from walking extraction

makes code more readable
test that we don't choke on sub-millisecond precision timestamps

(#4493)