Support for set_height in pango layout
Support for is_ellipsized? in pango layout
Merge pull request #210 from Vasfed/master

Support for set_height and is_ellipsized in pango layout

Patch by Vasily Fedoseyev. Thanks!!!
pango: use "-" for word separator in file name
pango: remove a trailing space
pango: remove trailing spaces
pango: use version check instead of function availability check
pango: add test for Layout#height and #height=
pango: use version check instead of function availability check

Because we can remove the ifdef easily after we increase required
Pango version. Less ifdef is better because ifdef reduces
maintainability.
pango: remove needless function check

pango_layout_get_font_description() is always available because we
require Pango 1.14 or later. The fucntion was appeared since 1.8.
pango: remove needless "is_"

Ruby uses "XXX?" style instead of "is_XXX?".