sync RMF to f58a8dfb1ab2f43d691966717c60851bb68c0e24

git-svn-id: https://svn.salilab.org/imp/trunk@16528 e91f8c7b-0e32-4433-a9ac-4502d39a4eab
fix printing of ParticleIndexes

git-svn-id: https://svn.salilab.org/imp/trunk@16529 e91f8c7b-0e32-4433-a9ac-4502d39a4eab
fix bug in (broken) external builds

git-svn-id: https://svn.salilab.org/imp/trunk@16530 e91f8c7b-0e32-4433-a9ac-4502d39a4eab
clean up and test re-reading of restraint particles in rmf files

git-svn-id: https://svn.salilab.org/imp/trunk@16531 e91f8c7b-0e32-4433-a9ac-4502d39a4eab