input xdata Array{Real}

read_ms now returns YData
comp_t0 computes t0 R!=1 + rwf

Computes matching in the charm sector 
Scaling + chiral extrapolations are missing

functions returns uwreal not a Vector{uwreal}

meff takes the absolute value of the correlator.
plots now include mu values

find_xmin to be tested (issues with double exponential fits)

juobs_linalg added, juobs deps extended (LinearAlgebra)

(juobs_obs, juobs_reader and juobs_tools)

ADerrors commit 9c41ec2e161e4826bfe0752be8bf2a0bc025759c 

Obs -> Corr (meff and dec_const_pcvc return Vector{uwreal})
2 linear_fit methods added

dec_const_pcvc is completed, new methods, Corr->Obs, Obs constructors added,  L normalization

juobs_obs added,   meff and plat_av moved to juobs_obs, Corr now includes y0,  syntax simplified(Symbol), Plots->PyPlot, LatexString support