Rename path_list to string_list

The name path_list was correct for the first usage of that data structure,
but it really is a general-purpose string list.

$ perl -i -pe 's/path-list/string-list/g' $(git grep -l path-list)
$ perl -i -pe 's/path_list/string_list/g' $(git grep -l path_list)
$ git mv path-list.h string-list.h
$ git mv path-list.c string-list.c
$ perl -i -pe 's/has_path/has_string/g' $(git grep -l has_path)
$ perl -i -pe 's/path/string/g' string-list.[ch]
$ git mv Documentation/technical/api-path-list.txt \
	Documentation/technical/api-string-list.txt
$ perl -i -pe 's/strdup_paths/strdup_strings/g' $(git grep -l strdup_paths)

... and then fix all users of string-list to access the member "string"
instead of "path".

Documentation/technical/api-string-list.txt needed some rewrapping, too.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

string-list.h

@@ -0,0 +1,28 @@
+#ifndef PATH_LIST_H
+#define PATH_LIST_H
+
+struct string_list_item {
+	char *string;
+	void *util;
+};
+struct string_list
+{
+	struct string_list_item *items;
+	unsigned int nr, alloc;
+	unsigned int strdup_strings:1;
+};
+
+void print_string_list(const char *text, const struct string_list *p);
+void string_list_clear(struct string_list *list, int free_util);
+
+/* Use these functions only on sorted lists: */
+int string_list_has_string(const struct string_list *list, const char *string);
+struct string_list_item *string_list_insert(const char *string, struct string_list *list);
+struct string_list_item *string_list_lookup(const char *string, struct string_list *list);
+
+/* Use these functions only on unsorted lists: */
+struct string_list_item *string_list_append(const char *string, struct string_list *list);
+void sort_string_list(struct string_list *list);
+int unsorted_string_list_has_string(struct string_list *list, const char *string);
+
+#endif /* PATH_LIST_H */