Merge branch 'jk/git-hash-cleanups'

The 'git_hash_*()' wrappers have been updated to be used consistently across the codebase instead of direct calls to members of 'struct git_hash_algo', and 'git_hash_discard()' has been made idempotent to simplify cleanups. * jk/git-hash-cleanups: hash: check ctx->active flag in all wrapper functions http: use idempotent git_hash_discard() csum-file: use idempotent git_hash_discard() hash: make git_hash_discard() idempotent hash: document function pointers and wrappers hash: convert remaining direct function calls hash: use git_hash_init() consistently