Fix #7
InfiniteWireZCenter calculation has been wrong for years (commit
edf8a45e271ebbd13f15328d6b656364cc08a37b) and was mistakenly also used
for FiniteWireZCenter since commit
f11dc566571a345e0ff925c783aa5e1f6eb3a2e4
replaced particle.in with upstream version
Added spin tracking with particle specific options.
Moved interpretation of particle specific options into TParticle class.
Fixed small issues when not using CGAL library
replacing with upstream  particle.h
replacing neutron.h with upstream version
fixed conflict with config.in when merging with upstream
Added some additional checks for invalid user input.
Switched on compiler warnings (excepting the ones produced by external
libraries).
current makefile