Spectacle 2.0

• added accelerated OpenGL graphics
• improved the default color scheme for readability
• added multi-rate algorithms, to increase resolution in the low frequency range
• adopted a more musically-relevant grid scale, and drawn minor grid lines
• added support of custom palettes in manually written theme files
• added a resizing handle
• eliminated the requirement of xxd for building
• renamed the standalone to avoid a conflict with existing programs