Project structure was reorganized.

This commit applies to issue #9 (Reorganize the project structure).

Project structure was reorganized. Benchmarks and unit tests were separated. For benchmarks was set Release build mode. Raw Makefiles were removed. Source code of Google test framework (v. 1.7) was added in the repository (some redundant build scripts of Google Test framework were removed). Broken changes: Visual Studio project files don't match with new project structure.

Changes was successfully tested on Linux host (gcc 4.8.1, cmake 2.8.11.2).