C++11 standard

This moves us to the C++11 standard, see some nice things and new programming approaches it brings: 
http://blog.smartbear.com/c-plus-plus/the-biggest-changes-in-c11-and-why-you-should-care/

I used automated migration with `clang-modernize` from latest llvm-3.4-svn, please let me know if you agree with the C++11 suggested methods - some are good (nullptr, auto), some are more like a matter of taste (range based for loops)-but can be simpler and avoid some typos/bugs.