AbstractFastHartleyTransforms.jl v0.1.2

Adding a new reference implementation for r2r transforms. (see #5 )

• FHTPlan/FHTPlanInplace have been replaced to BFFTPlan/BFFTPlanInplace
• Added R2RPlan/R2RPlanInplace for the implementation using r2r FFT interfaces

Full Changelog: v0.1.1...v0.1.2