Fix: Create custom JSS instance

To prevent manipulations on the default instance (like plugins setup)
affecting Styleguidist styles.

Fix: Omit component if propsParser returns an empty array (styleguidi…

…st#588)

Fix: Prefix generated by JSS class names

To prevent collisions when user app also uses JSS.

Fix: Inherit font-size to make em sizing work properly in components (s…

…tyleguidist#585)

Close styleguidist#584

Fix: Do not lowercase nested keys of example settings object, pass pr…

…ops to Preview component

Fix: Pass example file path to updateExample (styleguidist#583)

Close styleguidist#579.

Fix: Migrate to react-codemirror2 (styleguidist#574)

Closes styleguidist#573

Fix: Fix parsing of error about webpack loaders

Looks like they’ve changed format and our RegExp doesn’t work anymore.
Anyway their error is now better, we just need to add a proper docs
link.

Closes styleguidist#575.

Fix: Update syntax in an example inside “Add examples to this component”

Fix: Lock jss-isolate version because of a regression in the latest p…

…atch release

cssinjs/jss#561