Change: Rename some freetype things to fontcache.

The font cache supports more than just FreeType as a font provider, but still used freetype in some naming.

This now uses more suitable terms.

src/table/unicode.h

@@ -17,7 +17,7 @@ static const byte CLRA = 0; ///< Identifier to clear all glyphs at this codepoin
 /* Default unicode mapping table for sprite based glyphs.
  * This table allows us use unicode characters even though the glyphs don't
  * exist, or are in the wrong place, in the standard sprite fonts.
- * This is not used for FreeType rendering */
+ * This is not used for TrueType rendering */
 
 static const DefaultUnicodeMapping _default_unicode_map[] = {
 	{ 0x00A0, 0x20 }, // Non-breaking space / Up arrow