Version 0.10.4

Changes

• Added a pixelmap feature and example (#637)
• The location with a quad is reported in mouse events and point search functions (#635)
• Canvas elements can be rendered in quads on the canvas renderer (#634)
• Most features support visibility (#632)
• Colors can be specified with a greater variety of css methods, such as rgb() and rgba() (#636)
• Point annotations can scale with zoom (#628)