Modified TTFDataView to be able to create an instance from the buffer directly.

- Remove TrueType.createFromDataView()
- Add TrueType.createFromBuffer()
Add getGlyphById method.

- TrueType#getGlyphById()
- GlyfTable#getGlyphById()
Add toSVGPathString()

- SimpleGlyph#toSVGPathString()
- CompositeGlyph#toSVGPathString()