v1.2.7 New file browser, Sampler unison, and more

• Updated file manager in-plugin instead of system dialog - This is for compatibility with different daws on linux doing things weird! But it works for everyone :)
  
• Dependencies changed/updated
• Files reorganized for easier bug and development work - The gui is now its own file whew
  
• Sampler now has unison and different handling on envelopes - very cool 👍
  
• Slight stereo blending happens to even out panning on stacked left/right happenings
• Extra commented out sections removed from code
• New reverb "Simple Space" added
• Preset bank size expanded to 128
• Small bug fixes