Added capability for stripping multiple laters per step in HeapLang

See merge request iris/iris!783

Dump `siProp_scope` and use `bi_scope`. This is consistent with `uPred`.

See merge request iris/iris!786

Ensure that different `Cofe` proofs of `iProp` are convertible.

See merge request iris/iris!784

Use |-@{...} to avoid the need for casts (in tests)

See merge request iris/iris!785

Make inG instances local

See merge request iris/iris!780

GFunctors changed to a record

See merge request iris/iris!782

Prevent cbn from unfolding the 'heap_lang' term.

See merge request iris/iris!779

Extend `iInduction` with support for induction schemes containing `Forall`.

Closes #430

See merge request iris/iris!731

big_op: weaken all Absorbing conditions using TCOr and Affine

See merge request iris/iris!757

For all big_op lemmas which had an `Absorbing` condition, the condition
has now become an alternative between `Affine` and `Absorbing`. Thus the
lemmas are made more general. This change is spreading the use of the
`TCOr (Affine _) (Absorbing _)` pattern.

Stop `iAssumption` from unifying evar premises with `False`

See merge request iris/iris!772