Bump version number to 0.1.0-rc.3
Update URL of submodule 'viennagrid' to use HTTPS instead of SSH.

If you check out using SSH but don't have an SSH key in your user's SSH configuration directory, GitHub rejects your request to clone the repository where the submodule is. If you use HTTPS instead, GitHub allows you to clone the repository without requiring an SSH key. This is useful if you don't have an SSH key set up or if you don't have a GitHub user account.
Fix CMakeLists to generate distutils package when building target 'packagesrc'.

This command had been removed, but it turned out to be useful, most of all when the documentation cannot be built properly but you still need to generate the disutils package in order to install and use/test the Python package.
Merge branch 'hotfix-0.1.0-rc.3'