Fixed problems in dist and dist-src targets

Due to recent removal of viennacl.pdf in doc/ folder and auxiliary/ folder, some copy failures were encountered.
CMake: Added missing libviennacl/ to dist-target, ENABLE_UBLAS is no longer marked as advanced.

Users are likely to enable uBLAS, hence it's better not to hide this option by default.
VS 2012: Fixed some more complaints.

Mostly integer/fp conversion. One namespacing issue (add viennacl::) and include hierarchy polishing.