TRON: add a warning if initial guess is not within the bounds

[tmigot]

I noticed we don't projet the initial guess, so if verbose>0 we should probably send some warning

[Jay-sanjay]

@tmigot sir is it fine if, I add this condition in tronls.jl , tron.jl , trunk.jl , trunkls.jl , R2.jl , lbfgs.jl ,
if verbose > 0
error("Invalid input")
end

[tmigot]

Thanks for thé suggestion @Jay-sanjay
I think it should be a warning not an error and it only concerns TRON and TRON-NLS as they are the only handling bounds.

The warning message could be : Initial guess is not within bounds.

[dpo]

Also, the projection should happen.