Shift soft Higgs masses to meet tree-level EWSB conditions in lattice code

to respect the tree-level Slavnov-Taylor identity between the
goldstone boson and vector boson masses (in Rxi gauge for xi = 1).
See also: commit b4cf1673e26084bae8764403dbebf3e365b3427b,
          commit 933400fa0fb466058eb1d97e9232fa2d68abab97
meta/Lattice.m: treat unbound CContext[scope] as ""
Rename get_scale() to scl() in Lattice_model_interactions

so that it can be represented by the same name in a Mathematica
expression.
meta/Lattice.m: fix FindDependence[]

Before the fix, there were objects that FindDependence[] classified as
explicit dependencies even though they were not registered to
ToEnumSymbol[].
CNConstraintsToCCode[]: do not convert dependence list to string

so that dependence lists from multiple calls to this function can be
merged easily afterwards.
meta/Lattice.m: improve expression reality checks
Add ComplexLog() to handle negative mass^2
Clean up lattice code
Add first draft of lattice low-scale constraints
WrapText[]: do not append or trim any trailing newline

to make code formatting easier