Added 'catkin_make' support to CatkinResourceRetriever

[mkoval]

This pull request modifies CatkinResourceRetriever to locate Catkin packages by recursively searching the source space for package.xml files. This adds support for two important features:

1. support for devel spaces generated by catkin_make
2. support for packages named differently than their enclosing directory

I added unit tests for both catkin_make and catkin build style workspaces.

[psigen]

I'm assuming you assigned me to review this?

[mkoval]

Yup. I probably shouldn't review my own pull request. 😄

[psigen]

Would it make sense to put a CATKIN_IGNORE in one of the parent directories of the test workspace path so that the test packages don't get crawled if someone just checks the code out into their workspace? Or can we depend on the "no recursive package.xml" rule?

[mkoval]

Good question. In theory, we can rely on the "no recursive package.xml files" rule. I tested this with roscd and it seems to be true - I couldn't roscd my_package1.

[psigen]

Can you comment what this function does?

[psigen]

Looks pretty good overall, but I can't compile it until I fix some unrelated issues in my DART build.
Nice unit tests.

[mkoval]

I believe I resolved all of your comments.

[psigen]

Oh, as I was pulling this version to test, I found that I already had a local version of bugfix/catkin_cmake. Guess I found my implemetation 😓.

[mkoval]

@psigen Were you able to test this version? Are you satisfied with the pull request? 😄

[psigen]

Yeah, seems to work for me.