Log Message:
pangomm2.48: updated to 2.52.0

2.52.0 (stable):

* FontFamily: Add property_item_type(), property_n_items(),
  property_name(), property_is_monospace(), property_is_variable().
* FontMap: Add reload_font(), property_item_type(),
  property_n_items().

Build:
* Require pango >= 1.52.0.