Merge pull request #68 from utzig/v1_6_0

Updates for release 1.6.0
tree: cdb2e954de8bac62c1d3d3d0984f4f4c28667efe
  1. docs/
  2. versions/
  3. .gitignore
  4. doxygen-mynewt-core.xml
  5. Makefile
  6. README.rst