Keep hyperbolic LCSs within shear LCSs
Change function name: compute_ftle → ftle
Replace backward-time strainlines by forward-time stretchlines
Change eigenvector and eigenvalue input format in seed_curves_from_lambda_max

Input format changed to match output of eig_cgStrain
Update double gyre and Bickley jet demo scripts
Merge branch 'master' into dev
Update ocean dataset demo scripts
Update ocean data-set demo scripts
Change structure array input into separate input arguments

Functions like eig_cgStrain gathered multiple input arguments into a
structure array. This facilitated compact code writing, but was more
obscure. This commit separates structure arrays into multiple inputs.

Furthermore, optional input arguments are changed into input
parameters.
Update double gyre demo scripts for new syntax introduced in commit adec449d2e3b317fce024aa04d61ef519fd1989a
Change order of input arguments in eig_cgStrain
Improve double gyre demo script
Update double gyre demo script
Update demo scripts
Update double gyre demo scripts
Add nBisection input to poincare_closed_orbit_multi
Switch order of output arguments in eig_cgStrain and make number of
output arguments variable
Correct warning message format
Add warning message when main grid spacing is unequal
Reword error messages