Cuvec

- fix minor memleak (13)
- docs: fix typos
- build: misc framework updates

- minor documentation updates (12)

- fix `clang` builds (11)
- fix builds without SWIG (11)
- optimal test thread spawning

- fix CMake export target (10)
- document SWIG usage

- make CUDA optional (9)
+ make `__half`/`e` optional
- add CPU versions of examples
- add & update tests

- major SWIG updates (8)
+ expose `SwigCuVec<T>`
+ separate core (`swvec.i`) & example (`example_swig.i`) modules
+ update tests & examples
- update & tidy performance tests