Changed a warning in BAR to an error + added handling
Changed a warning in BAR to an error + added handling

Overflow in the solution to the BAR equations is now
caught so we can handle it explicitly.

kyleabeauchamp/pymbar,kyleabeauchamp/pymbar,Lnaden/pymbar,jchodera/pymbar,jchodera/pymbar,kyleabeauchamp/pymbar,choderalab/pymbar,wesbarnett/pymbar,mrshirts/pymbar,wesbarnett/pymbar,wesbarnett/pymbar,Lnaden/pymbar,jchodera/pymbar,choderalab/pymbar,jchodera/pymbar,wesbarnett/pymbar,choderalab/pymbar,mrshirts/pymbar,mrshirts/pymbar,Lnaden/pymbar,mrshirts/pymbar,kyleabeauchamp/pymbar