Tracking issue for next release series

[tarcieri]

This is a tracking issue for the next set of breaking releases which are currently under development on the master branch:

• aead v0.6
• async-signature v0.6
• cipher v0.5
• crypto-common v0.2
• digest v0.11
• elliptic-curve v0.14
• kem v0.3
• password-hash v0.6
• signature v2.3
• universal-hash v0.6

If need be we can subdivide this issue into separate issues for specific (or all) crates above.

[tarcieri]

The following are tracking issues for releases of important dependencies of the crates tracked in this issue:

• block-buffer v0.11, block-padding v0.4, inout v0.2: Tracking issue for next release series utils#1070
• hybrid-array v0.2.0: Tracking issue for v0.2.0 release hybrid-array#74
• rand_core v0.9: rand_core v0.9 support #1642

[tarcieri]

#1677 suggests merging async-signature into signature, which would eliminate the need for another async-signature release