Support binary notation.
merged branch thunderer/config-support-binary-notation (PR #8727)

This PR was submitted for the 2.2 branch but it was merged into the master branch instead (closes #8727).

Discussion
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[Config] Support binary notation.

This PR addresses issue #8066 . Binary notation is not caught by `is_numeric()` function so we need to implement it on our own.

Commits
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34f5bd8 [Config] Support binary notation.
[Config] fixed handling of negative integer in XML support