Add more extensive uiSchema actions

[mavarazy]

While using in internal project current set of actions for uiSchema proved to be insufficient, since many actions require more, then one modification to uiSchema object.

Proposed solution is to deprecate appendClass and replaceUi and replace them with a different set of actions uiAppend, uiOverride and uiReplace, which would take a subset of uiSchema as configuration.

uiAppend will append specific configurations to original uiSchema, only if provided string was not already part of uiSchema configuration.
uiOverride will replace specific configurations of original uiSchema
uiReplace will replace all configurations in original uiSchema

This should improve library usability.