Independent Build Process

This commit includes the compilation of the dynamic/static libraries
that compose <code>nupic.core</code>. They are generated by default on
<code>nupic.core/build/release</code> folder, however any user could change its
destination using <code>cmake -DPROJECT_BUILD_RELEASE_DIR=…</code> or <code>cmake -DPROJECT_BUILD_TEMP_DIR=…</code> command line.
Thought this option, Travis at <code>nupic</code> repo will compile the static
libraries and put them on <code>/external</code>folder.

The output of this library is a static library called nupic.core (I linked with HtmTest, TesteEverything, and all is ok.. :-) ). I'm also trying make CMake generate a dynamic library, but without success (problems with dynamic linking).

Note that neither <code>HtmTest</code> not <code>TestEverything</code> were included, they still
are hybrid and Python tests need be removed from them.

This PR replaces this:
 https://github.com/numenta/nupic.core/pull/32

fixes #4