WIP: Better (?) solution for explicitly instantiating some templates so
that they are available exported from the library (mostly for windows)
WIP: Create a list of symbols needed to be exported from libqpidmessaging.so
  and libqpitypes.so
WIP: slim down exported symbols in official API libraries
WIP: Probably need visibility flags at link time too
WIP: Added link map file to cut the number of symbols right down