Ignore .pickle files.
Small improvements to the MIMO simulator.
Ignore .out files anywhere.

Previously only ,out files in the tests folder were ignored.
Ignore files with *flymake* in the name.

These files are created by Emacs.
Cleaning and organization.
Replace np.sqrt with math.sqrt.

When calculating the square root of single numbers it is faster to use
the sqrt function from the math library, instead of the version in the
numpy library.
Cleaning and organization of the code
Implement the MRT and MRC MIMO schemes

Also include the unittests and changes to the apps/simulate_mimo.py file
to simulate these schemes.

Note that the decode method of the Blast MIMO scheme already does the
equivalent of MRC. Therefore, the MRC class was only added for
completion and simply inherits from the Blast class.