Fix decoding issue after buffer overflow. (#253)
Fix decoding issue after buffer overflow. (#253)

The bug was tickled when the capture buffer overflowed.
Though, it probably also manifests when are large or garbage message is
captured, and writes data through out the buffer.
When a smaller message comes in, the last entry which is typically the
post message gap, is not cleared. This could caused the decoder(s) to get
confused as they would be reading previous messages (or garbage) data.

- Fixes Issue #246
- No unit tests for this bug is only tickled 'on device' due to interrupt
  handling. Our unit tests don't really cover that aspect.
markszabo/IRremoteESP8266,markszabo/IRremoteESP8266,markszabo/IRremoteESP8266,markszabo/IRremoteESP8266