Bump version to 2.2.29dev
Change default options to sfdp_layout()
Fix degree-corrected entropy computation in NestedBlockState
Fix vertex/edge search with python::object properties
Randomize sweep order in sfdp_layout()

This fixes some strange bugs where deterministic position updates lead
to strange artifacts.
Remove redundant random_move parameter from mcmc_sweep() and related functions

To specify fully random moves, one should set the parameter "c" to
"float(inf)", as explained in the docstring.
Cosmetic docstring example improvements
Ignore self-loops when merging nodes in block graph
Improve speed of random_rewire() when parallel edges are not allowed

This also changes the semantics of random_rewire() when parallel edges
/ self loops are forbidden, but the initial graph contains them. Now,
instead of throwing an exception, the rewiring is attempted, with no
new parallel edges / self-loops being created. Under some
circumstances, if the degree sequence is graphical, eventually the
graph can become simple after sufficiently many sweeps.
Change default value for parameter 'c' in multilevel_minimize()
Remove redundant get_weight() method in BlockState and update get_ers() docstring
Docstring correction
Update citation information in docstrings
Fix bug in sfpd_layout() which causes positional artifacts
Bump version to 2.2.29