Adding medical workers and hospital interactions

[debog]

Added medical workers and their interactions to HospitalModel:

• Assign a certain percentage of workers in each community as medical workers (doctors/RNs). Specified as:

agent.med_workers_proportion (default: 0)

• Add interaction between medical workers and between medical workers and patients. The interaction transmissivities (doctor-to-doctor, doctor-to-patient, patient-to-doctor, patient-to-patient) are respectively specified by (default values in parentheses):

disease.xmit_hosp_d2d (0.01*xmit_work)
disease.xmit_hosp_d2p (0)
disease.xmit_hosp_p2d (0)
disease.xmit_hosp_p2p (0)

• Assigning a fraction of the medical workers as those dealing with the simulated disease(s). The fraction is specified by:

hospital_model.acute_medworkers_proportion (default: 0.2)

• Making survival/death probability of hospitalized agents dependent on hospital score that is computed from the number of patients in the hospital and hospital capacity that depends on number of available medical workers. The hospital capacity is computed from the number of patients a doctor can see (per day); this can be specified as:

hospital_model.num_patients_per_doctor (default: 50)

The hospital diagnostics (number of patients, load, number of active doctors, etc.) can be written as plot files by specifying:

hospital_model.write_pltfiles (default: false)

Note: All the new input parameters are optional, and with their default values, the code behaves exactly the same as development branch.