undo uninternsional changesin discretize
DOC: Change IRC link to HTTPS
warn if pydot version < 1.0.28 found by setup.py
added the minimum version for numpy
DOC: added info on cvxopt problems in MacPorts
fixed up robot_discrete example in tutorial
DOC TRIV: provide a bit more info in Example 1
Merge branch 'master' of https://github.com/tulip-control/tulip-control
DOC: updated robot_continuous.py tutorial + some rearrangement
DOC:small corrections in tutorial
TRIV: typo
format get_input docstring in epydoc
correct confusing exception mentioning old post_single
interface get_input to AbstractSysDyn
convert to new-style classes

affected classes:
	- Polytope
	- Region
	- LtiSysDyn
	- PwaSysDyn
	- HybridSysDyn
	- AbstractSysDyn

among others, this change avoids type() returning:
	<type 'instance'>
instead of the actual class name
check if Iterable provided to createLM

intead of using isinstance to check for Polytope.
This avoids type mismatch caused when the polytope module is reloaded.
An example is running robot_continuous.py in an IPython session,
then running another file that calls get_input.

Also, in get_input: pythonic iteration over target Region's polytopes
rename get_cell_id -> find_discrete_state, and refactor it
update abstract.__init__
example use of get_input, for developers
docstrings and style