fix compilation add dub.json
fix compile error

- array cast immutable to mutable in CTFE not supported
build examples
faster floor/ceil
faster findRootIllinois

- no x87 ops
store wavelet coefficients in a linear quadtree

- avoids the overhead of storing 4 pointers per 12-byte
  coefficients

- requires to preallocate space for all coefficients

- a bitfield is used to mark used coefficients.

- remove TempAlloc dependency (uses malloc/free)
pass quadrant to calcCoeffs
remove calcCoeffs.cc
optimize calcCoeffs by switching later
fix default value for stroke-width