Giving a mutable map-based context a try
Gave it a try - it is too slow.
Revert intmap based approach to contexts

This reverts commit a1b34631112e816502d85fe3ff409c8fb76eb56b.
Revert "Giving a mutable map-based context a try"

This reverts commit c0acf09f49e8be9f8d2843ad74c07d9dd422b1e2.
Fix sign distribution