Revert "Remove some needless includes"

This reverts commit 6382678a9d0a55cd0779366b35ab772d7511f5a7.
FIX: Samplemanager clobbering th1 with th2 dataset

Samplemanager runs LoadBedPostDataHelper() for each f,th,ph file it
finds.  This bug only appears if you have more than one of these files.
It would overwrite f1,th1,ph1 with f2,th2,phi2.  This has two issues:
 1. Most of the second dataset is very isotropic, causing the terrible
    tracking results observed.
 2. The second thread is left uninitialized, which further increases
    potential for chaos.