Merge pull request #225 from VectorCamp/feature/cleanup-compiler-warnings

Merge pull request #225 from VectorCamp/feature/cleanup-compiler-warnings

According to https://buildbot-ci.vectorcamp.gr/#/changes/93

most builds succceded and with no compiler warnings. The build failures were only on x86 and Arm for SIMDe builds: x86 because of a bug in SIMDe emulation of own x86 intrinsics in non-native mode and Arm due to clang, unsure if this is actually a bug in SIMDe or clang itself. All the remaining compiler warnings that were suppressed was because they were not possible to fix for the scope of this project.

This PR will close #170, code quality improvements however will continue with the integration of #222 or similar static code analyzer to CI and continuous refactoring.