Unit tests refactoring to use gtest_filters and reduce test executables

[kknox]

Similar to the benchmarking app, I think we are currently developing too many test executables. There is a lot of common framework code that belongs to each executable, and they might as well be the same executable where we add more unit tests with gtest_filters. Re: clFFT unit tests.

It might still make sense to group unit tests into 3 main executables, one to test L1 operations, another for L2 operations and a third for L3 operations.

[jpola]

There wasn't any decision made in #75 so by force :smiling_imp: I would like to start using boost::numeric::ublas here. It is a header template library so we don't need to change CMakeLists.txt files. Just start to use it by including blas::numeric::ublas...

[kknox]

Sounds good to me; I don't think that we would be doing anything in our test suite that is not covered in functionality with ublas. Also, it makes sense to use ublas since we do install boost with our build scripts.

[jpola]

Implemented in #99