USER: Beginning to make the switch to E, theta, phi to deal with the following issue - when Px, Py, Pz, E are output from AcquRoot (which is before Particle ID has been done) the Px,Py,Pz, E has a zero mass assumed but this isn't correct! Once particle ID has been done these values can be stored (ie. from GoAT) but before this, only kinetic energy, theta and phi should be output as they will not change. In a future commit, I will change E to T for improved clarity on this issue. 4 vectors are now formed using a calculated E, p, and theta and phi. Particle reconstruction was changed slightly to account for this switch, and the Add Particle class forms a TLorentzVector such that variables are calculated correctly for composite systems. Issues in the resulting spectra appear, for example the typical theta structure is not seen and the typical mass peak is not seen. More investigation to follow.