Change the maximum indentation size to 32 spaces in encoder

This is to free up bits from the flags parameter of json_dump
functions. I'm pretty sure no-one needs 256 spaces of indentation when
pretty-printing JSON values...

This is a backwards incompatible change.

doc/apiref.rst

@@ -618,7 +618,7 @@ can be ORed together to obtain *flags*.
 ``JSON_INDENT(n)``
    Pretty-print the result, using newlines between array and object
    items, and indenting with *n* spaces. The valid range for *n* is
-   between 0 and 255, other values result in an undefined output. If
+   between 0 and 32, other values result in an undefined output. If
    ``JSON_INDENT`` is not used or *n* is 0, no newlines are inserted
    between array and object items.
 

src/dump.c

@@ -41,7 +41,7 @@ static int dump_to_file(const char *buffer, int size, void *data)
     return 0;
 }
 
-/* 256 spaces (the maximum indentation size) */
+/* 32 spaces (the maximum indentation size) */
 static char whitespace[] = "                                ";
 
 static int dump_indent(size_t flags, int depth, int space, dump_func dump, void *data)

src/jansson.h

@@ -181,11 +181,11 @@ json_t *json_loads(const char *input, json_error_t *error);
 json_t *json_loadf(FILE *input, json_error_t *error);
 json_t *json_load_file(const char *path, json_error_t *error);
 
-#define JSON_INDENT(n)      (n & 0xFF)
-#define JSON_COMPACT        0x100
-#define JSON_ENSURE_ASCII   0x200
-#define JSON_SORT_KEYS      0x400
-#define JSON_PRESERVE_ORDER 0x800
+#define JSON_INDENT(n)      (n & 0x1F)
+#define JSON_COMPACT        0x20
+#define JSON_ENSURE_ASCII   0x40
+#define JSON_SORT_KEYS      0x80
+#define JSON_PRESERVE_ORDER 0x100
 
 char *json_dumps(const json_t *json, size_t flags);
 int json_dumpf(const json_t *json, FILE *output, size_t flags);