fixed errors from previous version of nrmlwr, added new surf variable
and reversed sign of the normal vector.
rectified error in nrmlwr, now we use test volume boundary to determine if enter or leaving volume
Merge pull request #104 from svalinn/nrmlwr_fix

Fixes for USRBDX crossing
Issue #101:  relocate id# in material card
Issue #101: remove extra text from material record
Rename to g_step and g_fire
Rename to f_normal
Rename to f_look
More renaming, remove commented-out code
Pull f_idnr into fluka_funcs
Incorporate WrapDN into fluka_funcs.cpp
Issue #108: Merging code with upstream changes