Finalizing the merging

See merge request !3

Julien's most updated code has all valence derivatives with the sign changed, so md_val needs to flip the sign. Also, the reader does not write "_d1, _d2" in the derivatives anymore for the new data files, so md_val does not look for "_d1, _d2". You need to select by hand which correlators are your valence derivatives, looking at the log file e.g.

This reverts commit f3531bef.

several functions, needs testing

functions for TSM runs.
read_mesons_correction -> read correction runs (exact + sloppy solutions)
corr_obs_TSM -> create Corr with <O_sloppy> + <O_correction>

Study and preliminary tests  on correlated fits

if der==0 -> do not call uwreal

plots modification in juobs_obs

added Mb physical in const

Class Corr extended with extra arguments \theta1 and \theta2 inherited  from CHeader. Required for 3-pt analysis with momentum injection

error array lengths

info==true && rw==nothing provides primary observable

<W> is a primary observable

several functions, needs testing

Now model labels in plots

Bayesian averaging method supports now averaging over two fit functions

Bayesian average method for one fit function added to juobs_tools.jl