fix typo
allow domain of an LTI system to be a region
update docstrings to reflect the fact that domain can be a region
DOC:fix typo
mv conversion from a strategy to a transducer from interfaces.gr1c to synth

because state substitutions (arbitrary finite domains) rely on lists from within GRSpec. The elements of these lists are constrained to be such, that syntactic substitutions can be performed in GRSpec. By pulling this part back to synth, all information available in synth can be used, eventually allowing for integer states in transition systems, a priori substitutions (outside of GRSpec) and less fragility.
fix imports, arguments and return values of moved function
rename var: spec0 -> spec
Merge branch 'master' into parity
implicit is evil: do not implicitly mask outputs

leave that to a graph transformer that belongs to preprocessing for exporting graphics.
rename: aut_xml2mealy -> load_aut_xml
add option to plot type of each AST node

and annotate networkx vertices with the AST nodes themselves
add new function: write_pdf for AST
add Const to AST node classes

because currently tulip's syntax is ambiguous: variables an values taken by variables that can range over an arbitrary finite domain are indistinguishable.
add Boolean formula flattening to python
simplify: arg need not be a list
bugfix: decorate op as property
pythonism