Format font metrix data to have one row for each glyph

This will make reviewing modifications easier, since the affected glyphs
will be more readily visible in the diff.
The formatting tool was applied to the existing data, instead of
regenerating the data, so the semantic content should be unmodified.

metrics/format_json.py

@@ -0,0 +1,16 @@
+#!/usr/bin/env python
+
+import sys
+import json
+
+data = json.load(sys.stdin)
+sep = "{\n"
+for font in sorted(data):
+  sys.stdout.write(sep + json.dumps(font))
+  sep = ": {\n  "
+  for glyph in sorted(data[font], key=int):
+      sys.stdout.write(sep + json.dumps(glyph) + ": ")
+      sys.stdout.write(json.dumps(data[font][glyph], sort_keys=True))
+      sep = ",\n  "
+  sep = "\n},\n"
+sys.stdout.write("\n}}\n");