V6
[Signal,Zeta,flag,NewxHI59,NewxHI754,NewxHI708,Newx16,Newx11]=Global21cm.run(Params)

Input:
Params - a matrix of size n-by-7, where n is the number of cases and 7 is the number of parameters (in this order):
fstar - star formation efficiency (e.g. 0.05). Input range: 0-0.5.
Vc -  minimum virial circular velocity (e.g. 16.5 km/s for atomic cooling). Input range: 16.5-76.5.
fx - X-ray efficiency (e.g. 1). Input range: 0-10.
tau - CMB optical depth (e.g. 0.06). Input range: 0.055-0.1.
alpha - the slope of the X-ray spectrum (e.g. 1 for sources with spectrum that goes as nu^(-1) ). Input range: 1-1.5.
nu_min - low cut-off of the X-ray spectrum (e.g. 0.2 KeV). Input range: 0.1-3.
Rmfp - mean free path of ionizing photons (e.g. 30 Mpc). Input range: 10-50.

Hence, a possible usage is:
[Signal,Zeta,flag]=Global21cm.run([0.05 16.5 1 0.06 1 0.2 30]);

Note: To run many cases efficiently do not use for-loop to run Global21cm.run() many times, but run it once with an n-by-7 matrix.

Outputs:
Signal - the expected 21-cm global signal, given for redshifts [5:0.1:50].
Zeta - the value of zeta (ionizing efficiency) used to produce the signal with the requested optical depth.
flag - vector of 4 elemnts, each can be 0 or 1:
	1 - The flag is 1 if the algorithm detected a possible problem.
	2 - The flag is 1 if zeta>fstar*40000 (Physical limitation from arXiv:1609.02312). In this case the returned signal will be empty (all zeros) .
	3 - The flag is 1 if neutral fraction is >0.16 at z=5.9 (Physical limitation from arXiv:1411.5375). 
	4 - The flag is 1 if neutral fraction is <0.11 at z=7.54 (Physical limitation from arXiv:1712.01860). 
NewxHI59 - xHI at z=5.9
NewxHI754 - xHI at z=7.54
NewxHI708 - xHI at z=7.08
Newx16 - nu at which xHI=0.16
Newx11 - nu at which xHI=0.11