New API in pangomm 1.50

Member Pango::ABSOLUTE_LINE_HEIGHT

Member Pango::ALL_PETITE_CAPS

Member Pango::ALL_SMALL_CAPS

Member Pango::BASELINE_SHIFT

Member Pango::CENTER

Member Pango::DECIMAL

Member Pango::FONT_SCALE

Member Pango::LINE_HEIGHT

Member Pango::PETITE_CAPS

Member Pango::RIGHT

Member Pango::SENTENCE

Member Pango::TITLE_CAPS

Member Pango::UNICASE

Member Pango::WORD