fix for crash bug #1728.

Moving _myAvatr to live in AvatarManager.  Application still has a
pointer to it.  Unfortunately the order of Application initialization
and destruction matters very much.
Merge branch 'master' of ssh://github.com/highfidelity/hifi into fix-particle-avatar-collisions
Merge branch 'master' of ssh://github.com/highfidelity/hifi into fix-particle-avatar-collisions

Conflicts:
	interface/src/Application.cpp
Merge branch 'master' of ssh://github.com/highfidelity/hifi into fix-particle-avatar-collisions

Conflicts:
	interface/src/Application.cpp
Merge pull request #1735 from AndrewMeadows/fix-particle-avatar-collisions

Fix crash on shutdown caused by duplicate delete on a QObject