[font/freetype] Vertically Writing (tategaki) support

We have to implement "TATEGAKI" for Asian font support. This word "tategaki" means vertically writing in Japanese.

Please see the screenshot Tategaki.png and the test program Tategaki.zip. Tategaki are usually used in Asian.

The tategaki font name begins by "@". For example, The font name "@MS Gothic" indicates a rotated font of "MS Gothic". Usually tategaki are used with font rotation. However arbitary font rotation will be later work.

Keywords are: FT_HAS_VERTICAL and FT_LOAD_VERTICAL_LAYOUT.

If FT_HAS_VERTICAL(face) is true, the face has vertical text layout. Then, you can use "@" plus font name. If you loads a glyph with FT_LOAD_VERTICAL_LAYOUT, the loaded glyph might have special layout (especially Asian-specific characters of class Tu or class Tr). In tategaki font (with @), the characters of class U and class Tr should spin 90 degrees counterclockwise. The character of class R has no difference in rendering. See freetype documents for details. See VerticalOrientation-17.txt for character classification.

The tategaki font names should be enumerated with "@", by EnumFontFamiliesEx function.