Use new environment and parameters on stack update.

Without this, changes in parameters specified in the update
will not propagate to resources.

Fixes bug: #1199189
Change-Id: Ic19b907e9dd12c121757cb7c6b3d0342415d0482
Handle conversion of MAP properties to JSON params

Since JsonParameter takes either a string or a Mapping, just pass the property
value directly as is done with strings and numbers

contributes to blueprint provider-resource

Change-Id: I71d5c0d9e3fcf3ffea9a89d2c37888faec35cd4a
Merge "Handle conversion of MAP properties to JSON params"
Merge "Use new environment and parameters on stack update."