Breaking changes:
-----------------

* Package signing and verification have been removed, to follow their removal from conda 4.3.  #1950

Enhancements:
-------------

* Avoid duplicate recreation of package index.  Speedup of 0-50%, depending on how extensively the recipe uses Jinja2 features.  #1954

Bug Fixes:
----------

* Fix cleanup of folders in outer variant loop - was causing incorrect packages on 2nd variant in windows builds  #1950
* Remove variant functionality from bdist_conda.  Its split packaging approach is incompatible.  #1950
* Fix import of _toposort from conda, reroute through conda_interface  #1952
* Match folder substrings more intelligently, for finding previous builds with --dirty  #1953
* Fix type error with --skip-existing and some conda recipes (Conda-build's internal conda.recipe was one).  #1956