[qtcontacts-sqlite] Normalize 'x' and 'X' DTMF chars to 'p'

The modem requires the 'p' character for pause; continue to accept
'x' in the DTMF input, but convert the normalized result.
[qtcontacts-sqlite] Update existing normalized phone numbers

Due to changes to the normalization code, we need to update existing
normalized data to match the results of the current code.
Merge pull request #144 from matthewvogt/dtmf-translate

[qtcontacts-sqlite] Normalize 'x' and 'X' DTMF chars to 'p'