C++98 compatibility

[inakleinbottle]

I think it is time that we seriously address the required C++ standards to build an compile new versions of Libalgebra.

Currently I think that the Libalgebra code is somewhere between C++98 compatible and C++11 compatible, which is not a good place to be.

I think the best course of action is to tag the current master branch as a release 0.8 (chosen for no particular reason), and make a new release tagged 1.0 in which we add C++11 as a requirement and adopt C++11 syntax, features, and idioms in the future. This will end the ambiguity in the code.

Any comments?