Shader notes and other visual adjustments

[liqMix]

• Uses shaders now instead of cached vertices for notes and such.
• Modified windows to be more thematic
  • perfect -> slap
  • hit -> slip
  • miss -> slop
• new hold note render with reactivation mechanics and point interval system
• updated header
• add background to gameplay screen
• updated lane background
• wobbly hold notes
• updated hit effect