Carlos Alves authored Jan 20, 2021 and Kurt Hindenburg committed Jan 22, 2021

Where it was possible:
- 'For' to STL copy or fill (it is like using memcpy and memset, faster
than for, the compiler decides the best algo to perform the task);
- 'For' + 'if' to 'where', it is faster and cleanner to read.

Changes in: PlainTextDecoder.cpp, HTMLDecoder.cpp, ColorScheme.cpp and
ExtendedCharTable.cpp