get_chi2 + fit_routine restructured 

fit_routine uses Optim
LsqFit deps removed.

functions that calls uwerr now includes wpm

cdata = [[data_r1[k], data_r2[k]] for k=1:length(data_r1)]
is no longer needed

mean(rw) was computed replica by replica

sum as variable

md_reader sign problem fixed

comp_t0 is generalized for polynomials of degree npol

uwerr missing
dof not reading length

indexes permuted in output read_ms
comp_t0 fixes rwf, plot plateau added, L mandatory

read_rw included. read_rw reads ms1.dat and pbp.dat

doc updated + minor redefinition

input xdata Array{Real}

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