More algebra (some axioms)
`Self` is an alias to `Top` for top theory.
`ppx` extension for detecting catch-all clauses.
Fix proofs in Ring.ec
add iterators on form
add function EcEnv.Ax.all as for EcEnv.Op.all
improve « print » command
improve « search » command:
- the command search now except a list of operators name
  it returns all lemmas talking about conjonction of the operators
  example:
   search ( * ) (+).
In matching, when finding selection, use conversion instead of alpha-equivalence.
[int] now has a builtin induction principle.
Progress in Ring.ec
No implicit arguments for local hypothesis.
Ring.ec: equip int for ZMod + progress.
Revert not clearing introduced variables by the `elim` tactic
Merge branch '1.0' of git://ci.easycrypt.info/easycrypt into 1.0