Merge branch 'mp/diff-algo-config'

Add diff.algorithm configuration so that the user does not type
"diff --histogram".

* mp/diff-algo-config:
  diff: Introduce --diff-algorithm command line option
  config: Introduce diff.algorithm variable
  git-completion.bash: Autocomplete --minimal and --histogram for git-diff

diff.h

@@ -336,6 +336,8 @@ extern struct userdiff_driver *get_textconv(struct diff_filespec *one);
 
 extern int parse_rename_score(const char **cp_p);
 
+extern long parse_algorithm_value(const char *value);
+
 extern int print_stat_summary(FILE *fp, int files,
 			      int insertions, int deletions);
 extern void setup_diff_pager(struct diff_options *);