travis: use suppression list to suppress warnings.
testsymboldatabase: run symboldatabase32, probably someone forgot to implement this.
testbool: same for checkComparisonOfBoolWithBool
testsuite: according to cppcheck, the function printTests() is not used, remove it.
testsuite: remove function todoAssert() which is unused according to cppcheck.
testcmdlineparser: comment out unused functions fileListStdin(), ignorepaths{1-4}(), ignorefilepaths{1,2}()
travis: also check "test" directory while ignoring test.cxx