obake 0.7.0

This new release of obake comes with various important developments:

• obake is now based on C++20 rather than C++17,
• an initial implementation of the power series class,
• noticeable speedups in the exponent packing code,
• compatibility with the re-branded oneTBB library.

Additionally, obake now depends on mp++ >= 0.23, and a few backwards-incompatible API changes were introduced as well. The full changelog, as usual, is available here:

https://bluescarni.github.io/obake/changelog.html