Merge: More binary operators

The first part of the PR cleanup and factorize some things related to the operators in the grammar and the AST.
Then the four bitwise operators are added.

Close #1271 unless some more thing is added to it (like generalized unary operators)

Note: as usual, github is useless when the parser is regenerated, so review the individual commits if you prefer.

Pull-Request: #1295
Reviewed-by: Lucas Bajolet <r4pass@hotmail.com>

diff --cc src/semantize/typing.nit
Simple merge