Merge branch 'jk/signal-cleanup'

* jk/signal-cleanup:
t0005: use SIGTERM for sigchain test
pager: do wait_for_pager on signal death
refactor signal handling for cleanup functions
chain kill signals for cleanup functions
diff: refactor tempfile cleanup handling
Windows: Fix signal numbers

diff --cc .gitignore
Simple merge

diff --cc Makefile
Simple merge

diff --cc builtin-clone.c
Simple merge

diff --cc diff.c
Simple merge

diff --cc http-push.c
Simple merge