* Set warning level to /W3 for MSVC to catch more warnings
* remove several excluded checks for clang
* removed several unused variables
* Hide warnings qwt
* add missing parentheses in logical expressions
* Remove double check on same logical expression
* Janitor : Improve robustness
* Guard nullptr access
* Limit the curve points to incoming from/to curve point index range
Co-authored-by: magnesj <magnesj@users.noreply.github.com>