Commits
![Steve Underwood](https://secure.gravatar.com/avatar/270cb905887a8d5c471d31ae8c7743c2.jpg?s=96&d=mm)
Steve Underwood committed bc13e944c63
Changes to the signaling tone detector to detect concurrent 2400Hz + 2600Hz tones. This passes voice immunity and other key tests, but it bounces a bit when transitions like 2400 -> 2400+2600 -> 2600 occur. Transitions between tone off and tone on are clean.