Merge branch 'maint-1.6.0' into maint

* maint-1.6.0:
User-manual: "git stash <comment>" form is long gone
add test-dump-cache-tree in Makefile
fix typo in Documentation
apply: fix access to an uninitialized mode variable, found by valgrind

diff --cc Documentation/technical/api-strbuf.txt
Simple merge

diff --cc Documentation/user-manual.txt
Simple merge

diff --cc Makefile
Simple merge

diff --cc builtin-apply.c
Simple merge