SDE Integration function cleaned up

Removed support for coupling -not used and implementation was poor. Removed upper limit in integration that sometimes causes instability when bad parameters are used. Removed support for numeric connection matrices.

Signed-off-by: Andrew D. Horchler <adh9@case.edu>
Cleaned up initial condition function.

Now uses the new shc_lv_mintransitiontime().

Signed-off-by: Andrew D. Horchler <adh9@case.edu>
New mean period function to replace neighborhood-finding function

The new shc_lv_meanperiod() can be used to simulate the nonlinear SHC and the resultant mean period constant(s) can then be used in a simple fitting equation to find the period as a function of arbitrary noise. The simple fitting functions will soon be added. This replaces the much more fragile and abstract neighborhood-finding function shc_lv_neighborhood().

README and Contents.m have been updated. shc_lv_invpassagetime has been removed from the listing and will likely soon be removed from the project.

Signed-off-by: Andrew D. Horchler <adh9@case.edu>