cppcheck: upgrade to version 1.66 on travis

Also, fix all warnings that are found by new cppcheck version.
Merge pull request #138 from toxeus/updateCppcheck

cppcheck: upgrade to version 1.66 on travis
cppcheck: fix noCopyConstructor
cppcheck: fix passedByValue
cppcheck: fix postfixOperator
Merge pull request #140 from toxeus/fixNoCopyConstructor

cppcheck: fix 3 warning types
cmake: OSX fix protobuf problem on Chris Notebook