- XLAL_INIT_MEM(x) sets the memory of variable 'x' to zero
- removed all (identical) previous local definitions of that macro
- added C99 convenience-macro XLAL_INIT_DECL(x) for declare+initialize a
  variable x, as in: INT4 XLAL_INIT_DECL(myvar);
- refs #1091
Original: 29d91768f90864116a06e2de523d728f2620b4d2