Fix two README.md typos
List homebrew dependencies for OS X
Remove reference to "configure.sh" (?)
Add support for Mask Write Register
Add support for 230400 baudrate
Another quick workaround for deficient OS (closes #63)

It will better to code something such as:
https://github.com/crossroads-io/libxs/blob/master/src/err.cpp

I don't intend to rewrite glib neither :(