moving overburden pressure calculation into base class
cleanup on last commit: base class overburden_pressure()
Implemented #112 in this branch.  This removes following functionality: -bmr_enhance, -thk_eff, -sliding_scale.  (Removed sliding_scale mechanism from PISMMohrCoulombYieldStress; see #114; sliding_scale mechanism is now broken.)  Proceeding to test in this branch.
removing -thk_eff options ... no big sign of trouble in tests (yet)
updating scripts: remove -thk_eff and replace -diffuse_bwat
Merge branch 'dev' into bwp-in-hydro
resolve (nonissue) conflicts from merge of dev
Merge branch 'dev' into bwp-in-hydro
Merged 84aa00 from dev.  Works for me.  Closes #109.
working on including cell_area the right way in all PISMHydrology objects; will not compile ... but I need to take a break
implements #117 in this branch; identifies the pointwise update action of PISMTillCanHydrology and its derived PISMDiffuseOnlyHydrology; clarifies marginal mass loss reporting
Merge branch 'dev' into bwp-in-hydro
fix typos found by pacman pedantic
Clarifying allocation and communication in PISMLakesHydrology and PISMDistributedHydrology.  Only the latter needs hydraulic_potential().
draft of bit of code to get A,n from stressbalance's flowlaw
glen parameters n,A drawn straight from existing configuration parameters in PISMDistributedHydrology
all constants are configurable in PISMDistributedHydrology
pressure update in PISMDistributedHydrology handles when to use laplacian in pressure update the same way as notes and Matlab codes
dealt with the regrid FIXME
initialization of P in PISMDistributedHydrology is the way I want it ... I think