Merge pull request #147 from slayoo/master

more intuitive messages in Cmake
getting rid of some warnings and adding VERBOSE=1 to make command in .travis.yml
use target_link_libraries to link blitz in debug mode
adding default case to a switch
Merge pull request #153 from mwarusz/master

getting rid of some warnings and adding VERBOSE=1 to make command in .tr...
using Release mode in most places to economise memory usage