Disallow `--libraries <file>:<library>:<address>` format

[cameel]

Abstract

The --libraries option accepts both <file>:<library>:<address> and <file>:<library>=<address> as argument. From now on only accept the latter.

Motivation

We originally accepted only the format with :. The one with = was introduced in #10707 to make the syntax less ambiguous visually (though note that it's not ambiguous to parse since neither the library name, nor the address can contain :). Together with the removal of support for unqualified library names (#12145) this will make command-line option parsing simpler and more regular.

Specification

• Report an error when the value does not contain the = sign.
• Update docs to remove mentions of the old format.

Backwards Compatibility

This is a breaking change to command-line interface.