Update getting-partial-results-using-projection-api.markdown

1. Remove nested path limitation as projection now support this
2. Add support for iterator as GS iterator now supports projections
Update getting-partial-results-using-projection-api.markdown
Update getting-partial-results-using-the-projection-api.markdown

1. removed nested projection limitation
2. added support for space iterator
Merge pull request #8 from eitany/patch-1

Patch 1