Slight modofication of semiclassical propagator.

NOTE: We should make this setting a configuration parameter.
New processing splitting methods
Semiclassical propagator based on processing method 764
Semiclassical propagator based on splitting method L42
Semiclassical propagator based on splitting method L84
Enable new semiclassical propagators
Remove redundant parameter definitions
New perturbed splitting methods of order (2s, 2)
Documentation for new splitting methods
Clean up processing splitting methods
Documentation of processing splitting methods
Clean up Kahan/Li splitting integrators
Fix perturbed splitting methods to match ABA pattern
Adapt propagators to new code structure
Merge branch 'smcu'