adding  E156B in list of seven_bit_modems


git-svn-id: http://asterisk-chan-dongle.googlecode.com/svn/trunk@30 a58c22ac-2eae-ab4a-0208-e3dbcd11fcda
fix rev no


git-svn-id: http://asterisk-chan-dongle.googlecode.com/svn/trunk@31 a58c22ac-2eae-ab4a-0208-e3dbcd11fcda
fix for issue 118, may be wrong


git-svn-id: http://asterisk-chan-dongle.googlecode.com/svn/trunk@32 a58c22ac-2eae-ab4a-0208-e3dbcd11fcda
added CHANNEL(dtmf) reading and writing


git-svn-id: http://asterisk-chan-dongle.googlecode.com/svn/trunk@33 a58c22ac-2eae-ab4a-0208-e3dbcd11fcda
fix revno


git-svn-id: http://asterisk-chan-dongle.googlecode.com/svn/trunk@34 a58c22ac-2eae-ab4a-0208-e3dbcd11fcda