Update and rename src/README.md to CONTRIBUTING.md

This way, GitHub notifies people about this document when they try to make a pull request.
added timestamps to LogUtil.
Use std::chrono elements
Remove nonexistent boost submodule (repo deleted)
Merge #43 with changes
Update submodules
Merge pull request #44 from cpluspluscom/remove-boost-submodule

Remove nonexistent boost submodule (repo deleted)
Recommendation: delete your local repo and re-clone - removing submodules is still a bit finicky in git
Merge branch 'master' into cmake
Remove reference to boost submodule