Fixes #319

This helps async proof checking (see
iris/iris!406 (comment 46759)).

Done with
```
gsed -i 's/seal \(.*\)\. by eexists. Qed./seal \1. Proof. by eexists. Qed./' \
  $(find theories/ -name '*.v')
```

And checked by inspecting the output of:
```
git grep '\bseal\b'|fgrep -v 'Proof. by eexists. Qed.'
```

Gregory Malecha authored 5 years ago and Robbert Krebbers committed 5 years ago

- remove "odd" comment
- move atomic triples to bi_scope

Use `_inv` for the reverse direction.

This feature is now deprecated in Coq master (see
https://github.com/coq/coq/pull/7791).

Instead of passing a partially-applied lemma directly to Hint Resolve,
first create a definition and then make that reference a hint.

Also refactor the proofs to make better reuse of existing lemmas.

This fixes the problem in iris/iris!275 (comment 42062)

The general idea is to first import/export modules which are further
than the current one, and then import/export modules which are close
dependencies.

This commit tries to use the same order of imports for every file, and
describes the convention in ProofGuide.md. There is one exception,
where we do not follow said convention: in program_logic/weakestpre.v,
using that order would break printing of texan triples (??).

We have these instances for all other logical operations too to support
setoid rewriting in both directions.