remove calcCoeffs.cc
optimize calcCoeffs by switching later
fix default value for stroke-width
blitter_detail.package
fix Color32 SSE routine

- use 64-bit memory operands
use minima for test timings
replace deprecated unordered float comparison ops
replace deprecated std.metastrings.Format!
enable warnings and deprecations
add dub.json for tests and ignore .dub folders
fix tests/benchmark

- add first blit benchmark
add .editorconfig