WebAudio examples

• music
• music through a closed door (low pass filter)
• music through a door (open/close)
• music through a door (open/close) to the right
• in a big room (echo), music through a door (open/close) to the right
• music from a big room (echo) through a door (open/close) to the right
• music with a "slow down everything" button
• example 4 implemented in Brython (music through a door (open/close) to the right)