Dd

- require `pydot >= 1.2.2`


API:

- change quantification syntax to `\E x, y: x`
- add renaming syntax `\S x / y, z / w: y & w`
- class `BDD` in `dd.bdd`, `dd.autoref`, `dd.cudd`:
- add operators `'ite', '\E', '\A'` to method `apply`
- add methods `forall` and `exist` as wrappers of `quantify`
- add method `_add_int` for checking presence of
a BDD node represented as an integer
- add method `succ` to obtain `(level, low, high)`
- class `cudd.BDD`:
- add method `compose`
- add method `ite`
- add method `to_expr`
- class `cudd.Function`:
- add method `__int__` to represent CUDD nodes
uniquely as integers (by shifting the C pointer value to
avoid possible conflicts with reserved values)
- add method `__str__` to return integer repr as `str`
- add attribute `level`
- add attribute `negated`
- module `cudd`:
- add function `restrict`
- add function `count_nodes`
- remove "extra" named `dot`, because `pydot` is now required

BUG:

- `dd.bdd.BDD.dump`: if argument `roots is None` (default),
then dump all nodes
- `dd.autoref.BDD.compose`: call wrapped method correctly

API:

- `dd.bdd.BDD.rename`, `dd.bdd.image`, `dd.bdd.preimage`: allow non-adjacent variable levels
- `dd.bdd.BDD.descendants`:
- arg `roots` instead of single node `u`
- iteration instead of recursion
- breadth-first instead of depth-first search
- `dd.bdd.BDD.dump`:
- dump nodes reachable from given roots
- dump only variable levels and nodes to pickle file
- correct error that ignored explicit file type for PDF, PNG, SVG
- `dd.bdd.BDD.load`:
- instance method to load nodes
- `dd.bdd.to_pydot`:
- add arg `roots`
- hide methods that dump and load entire manager
- `dd.bdd.BDD._dump_manager` and `_load_manager`
- remove `dd.autoref.Function.from_expr`

- install without extensions by default
- try to read git information, but assume release if this fails for any reason

- optionally import `gitpython` in `setup.py` to retrieve
version info from `git` repo.
- version identifier when `git` available:
`X.Y.Z.dev0+SHA[.dirty]`
- require `psutil >= 3.2.2`
- require `setuptools >= 19.6` to avoid `cython` affecting `psutil` build
- detect 64-bit system using `ctypes.sizeof` for CUDD flags

API:

- `dd.cudd.BDD.__cinit__`:
- rename arg `memory` -> `memory_estimate`
- assert memory estimate less than `psutil.virtual_memory().total`
- add arg `initial_cache_size`
- `dd.cudd.BDD.statistics`:
- distinguish between peak and live nodes
- cache statistics
- unique table statistics
- read node count without removing unused nodes
- `dd.cudd.BDD.configure`:
- accept keyword args, instead of `dict`
- first read config (returned `dict`), then set given values
- reordering
- garbage collection
- max cache soft
- max swaps
- max variables per reordering
- `dd.bdd`, `dd.autoref`, `dd.cudd`:
- add method `BDD.copy` for copying nodes between managers
- add method `BDD.rename` for substituting variables
- deprecate functions `rename` and `copy_bdd`
- add method `dd.cudd.BDD.sat_iter`
- add function `dd.cudd.count_nodes_per_level`
- add functions that track variable order when saving:
- `dd.cudd.dump`
- `dd.cudd.load`

- add user documentation
- support Python 3
- require `pydot3k` in Python 3, `pydot` in Python 2
- expose more control over CUDD configuration

API:

- add `dd.cudd.BDD.configure`
- do not set manager parameters in `__cinit__`
- rename `BDD.False` -> `BDD.false` (same for “true”), to avoid syntax errors in Python 3
- remove `dd.bdd.BDD.add_ast`
- `dd.cudd.reorder` invokes sifting if variable order is `None`
- default to pickle protocol 2