Updates to GeneralHLTOffline

In agreement with TSG, we have made several updates to GeneralHLTOffline. 

Removed:
- All eta, phi, and eta vs phi plots.

Current set of plots produced:
- One rate plot for all HLT paths in main folder;
- For each dataset, one rate plot of HLT paths of that dataset;
- For each path, one rate plot of the HLT filters of that path.