#5895 - Fixed potential signed integer overflow in Checkother:getvalue. Added regression test.
Refactorization in timer.cpp (#5902), Removed misleading comment in symboldatabase
Improved testing of AST, added unit test for #5787
travis: replace kernel check with clang check.

Check clang instead of kernel, which is a lot faster.
Make clang check failure fatal to the build.
travis: run test_matchcompiler.py
travis: move CHECK_INTERNAL check up, remove "SRCDIR=build VERIFY=1" job in favor of "MAKEFLAGS="HAVE_RULES=yes" SRCDIR=build VERIFY=1"
travis: add -DCHECK_INTERNAL to the VERIFY=1 job to automatically fetch issues like #5869 via travis
travis: run cppcheck with --exception-handling where it matters.