Bug fix for event detection

Small bug fixed in how event termination was detected across dimensions. Also, zero crossing detection is now strict, i.e., tangent-only is not detected in order to avoid triggering multiple events or events at initial conditions. State vector passed to EventsFUN is "columnized."

shc_zero() still needs interpolation and possible handling for an arguments list separate from shc_lv_integrate().

Signed-off-by: Andrew D. Horchler <adh9@case.edu>
Improved location of initial conditions on SHC manifold

shc_lv_ic() is completely re-worked. It is probably slower, but much more robust. It may handle SHC contours (chains) or other more general structures too, but this has not been tested. It now optionally takes the input parameter MU.

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