Support for "pattern" in the json-schema types

[nknapp]

This is actually an issue for bootprint-json-schema.
The "pattern" property should be display in the datatype-partial of the bootprint-schema project.

Testcases are currently written in this project and there should be one for this issue as well (sometime this might be consolidated, but currently, test cases are only set up here and no other project is using bootprint-json-schema.

[nknapp]

Extracted from of #1