Removes unused tower width argument
Cleans up photon energy in tower function
Cleans up photon energy in cluster function
Changes global fit int arguments to unsigned

Removes test for number of clusters to be 1 or greater.
Uses at() method to access tower width elements
Renames variables in 1-photon fit for more clarity
Enforces degrees of freedom range with std::max
Cleans up 1-photon fit function
Protects against 1-photon fit finding no photons
Cleans up 2-photon fit function
Moves 2-photon fit parameter setup into function
Moves fit parameter function to unnamed namespace
Set random number with Uniform()
Protects 2-photon fit finding other than 2 photons
Uses std::max to enforce degrees of freedom
Changes 2-photon parameter helper to struct
Moves 1-photon fit parameter setup to a struct
Moves global fit parameter setup to a struct
Clean up photon validation function