Python 0.3.2

Minor feature release

Breaking changes

• Change several methods (simplify(), trees(), Tree()) so most parameters
  are keyword only, not positional. This allows reordering of parameters, so
  that deprecated parameters can be moved, and the parameter order in similar functions,
  e.g. TableCollection.simplify and TreeSequence.simplify() can be made
  consistent (@hyanwong, #374, #846, #851)

Features

• Tree accessor functions (e.g. ts.first(), ts.at() pass extra parameters such as
  sample_indexes to the underlying Tree constructor; also root_threshold can
  be specified when calling ts.trees() (@hyanwong, #847, #848)

• Genomic intervals returned by python functions are now namedtuples, allowing .left
.right and .span usage (@hyanwong, #784, #786, #811)

• Added include_terminal parameter to edge diffs iterator, to output the last edges
  at the end of a tree sequence (@hyanwong, #783, #787)

• #832 - Add metadata_bytes method to allow access to raw
  TableCollection metadata (@benjeffery, #842)

• New tree.is_isolated(u) method (@hyanwong, #443).

• tskit.is_unknown_time can now check arrays. (@benjeffery, #857).