Change the base classes in the pyabc.i file to use the
collections.abc module instead of collections due to the deprecation
of the classes in the collections module in Python 3.7.
This is the (incomplemete) log produced by svnmerge.py:
Merged revisions 10405-10409,10420-10422,10426,10438,10445,10451,10454-10465,10467,10473-10475,10485,10488-10489,10493-10495,10497,10509-10510,10513-10514,10517,10520,10525,10528-10529,10533-10535,10554-10557,10570,10573,10593,10614,10666-10669,10673,10678,10687,10690,10704-10706,10731,10744,10750-10752,10755,10759,10770,10775-10776,10813,10819 via svnmerge from
https://swig.svn.sourceforge.net/svnroot/swig/branches/gsoc2008-bhy
git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk@10834 626c5289-ae23-0410-ae9c-e8d60b6d4f22