.gitignore: ignore generated files

Signed-off-by: Erik Bernoth <erik.bernoth@gmail.com>
conn.py: Implementing connection layer

The connection layer is the lowest abstraction layer of the MONK framework.
Its task is to interact directly with different types of connections. Some
logic is implemented via the State design pattern, and a cmd() method is
implmented as general interface for all connections. This cmd() method sends
a shell command to the target device and returns its standard output and some
additional information, e.g. the prompt or the return code of the shell
command.

See GitHub Issue #72

Signed-off-by: Erik Bernoth <erik.bernoth@gmail.com>
dev.py: Implementation of the device layer

The device layer is the central layer of the MONK framework. Its task is to
abstract a target device in an object, offering the same cmd() interface as the
connection layer, while handling more errors and many different connections for
the user. By using this layer it should be possible to focus on the interaction
with the target device without worrying how the object and the device actually
communicate with each other.

See GitHub Issue #72

Signed-off-by: Erik Bernoth <erik.bernoth@gmail.com>