Merge branch 'ap/merge-backend-opts'

* ap/merge-backend-opts:
  Document that merge strategies can now take their own options
  Extend merge-subtree tests to test -Xsubtree=dir.
  Make "subtree" part more orthogonal to the rest of merge-recursive.
  pull: Fix parsing of -X<option>
  Teach git-pull to pass -X<option> to git-merge
  git merge -X<option>
  git-merge-file --ours, --theirs

Conflicts:
	git-compat-util.h

git-compat-util.h

@@ -199,6 +199,7 @@ extern void warning(const char *err, ...) __attribute__((format (printf, 1, 2)))
 extern void set_die_routine(NORETURN_PTR void (*routine)(const char *err, va_list params));
 
 extern int prefixcmp(const char *str, const char *prefix);
+extern int suffixcmp(const char *str, const char *suffix);
 
 static inline const char *skip_prefix(const char *str, const char *prefix)
 {