Regression tests: split the collect test into two, moved armgcc download location

This pull request does two things:
* Splits the Rime collect test into two, one lossy and on non-lossy. This is because the tests take too long to run as a single test. As part of this change, some of the `.csc` file paths also needed to be updated.
* Change the armgcc download location away from mentor.com, where it might change, to a location at github.com.

There are still issues with travis, which seems to stem from some form of JNI problem, but this will at least solve the timeout problem for the collect tests.