fix CT::Vector
cleanup CT::Vector, CT::Int, add operation CT::min

- change default paramter of CT::Int
- remove code duplication for CT::min, CT::mul, CT::add, CT::volume  and CT::Dot
- add new operation CT:min
add traits for type limits

- add traits for type limits
- change dummy from integral type to a real type (boost::mpl::na)
change documentation for template parameter dummy
delete dummy, change documentation
Merge pull request #224 from psychocoderHPC/fix-CTVector

Fix CT::Vector