Pyhumod: Better support for MacOS X

Last week I improved support for MacOS X by

• defaulting to MacOS specific serial port names
• Changing serial port baud rate to 115200, which is a default one for the modem and MacOS' pppd likes it much better too.

Use the mercurial repository to get the latest features:

hg clone https://pyhumod.googlecode.com/hg/ pyhumod