Makefile comments updates and reordering to clarify knobs used to
choose SHA implementations.
* ab/sha-makefile-doc:
Makefile: discuss SHAttered in *_SHA{1,256} discussion
Makefile: document default SHA-1 backend on OSX
Makefile & test-tool: replace "DC_SHA1" variable with a "define"
Makefile: document SHA-1 and SHA-256 default and selection order
Makefile: document default SHA-256 backend
Makefile: rephrase the discussion of *_SHA1 knobs
Makefile: create and use sections for "define" flag listing
Makefile: correct DC_SHA1 documentation
INSTALL: remove discussion of SHA-1 backends
Makefile: always (re)set DC_SHA1 on fallback
projects / thirdparty / git.git / commit
