Expose noAnalogWrite() function to end PWM output on a pin. [imported]

[cmaglie]

This is Issue 581 moved from a Google Code project.
Added by 2011-08-16T21:58:53.000Z by dmel...@gmail.com.
Please review that bug for more context and additional comments, but update this bug.

Original labels: Type-Enhancement, Priority-Medium, Component-Core

Original description

This is basically the current turnOffPWM() function in wiring_digital.c. We should just rename it and expose it in the API.