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
12a4856545