We want to make PurpleContact derivable so that we can subclass it with
PurpleAccount. This will make things easier for everyone as we start moving
everything to PurpleContact as an account will just be a contact.
Testing Done:
Ran the unit tests and built the docs.
Reviewed at https://reviews.imfreedom.org/r/2081/
# UPDATING VERSION NUMBERS FOR RELEASES
#
# The version number is:
# <major>.<minor>.<micro><extra>
#
# micro += 1
#
# If any functions have been added to libpurple, Pidgin, or Finch:
# micro = 0
# minor += 1
#
# If backwards compatibility has been broken in libpurple, Pidgin, or Finch:
# micro = 0
# minor = 0
# major += 1
# purple_soversion += 1
#
# extra should be similar to one of the following: