changed some function names to make better sence, added additional legendre moments to allow for production and annihilation kernels rather then old way for this interaction.  Adjusted epannhil_Phi0_BRT06 to epannhil_Phi_Bruenn which accepts a few more arguements for generality
change function names a little bit
added equation reference
added routines for getting ep-annihilation kernels and building them into a table. added flags (off by default)