Merge pull request #384 from kiryl/warnings

Add more -W flags to CFLAGS

diff --cc CMakeLists.txt
Simple merge

diff --cc src/cache.c
Simple merge

diff --cc src/commit.c
Simple merge

diff --cc src/commit.h
Simple merge

diff --cc src/config_file.c
Simple merge

diff --cc src/mwindow.c
Simple merge

diff --cc src/odb_loose.c
Simple merge

diff --cc src/odb_pack.c
Simple merge

diff --cc src/refs.c
Simple merge

diff --cc src/remote.c
Simple merge

diff --cc src/repository.c
Simple merge

diff --cc src/revwalk.c
Simple merge

diff --cc src/signature.c
Simple merge

diff --cc src/tree.c
Simple merge

diff --cc tests/t12-repo.c
Simple merge