License expressions not parsed correctly causing incorrect license determination (silently ignoring potentially problematic licenses)

[rafalsatl]

For license strings containing logical operators as defined for SPDX (or similar to them):
https://spdx.github.io/spdx-spec/v2-draft/SPDX-license-expressions/

License checker currently produces incorrect and dangerous results during the flatten -> license calls:
Input:
name = "simpler-sidebar"
version = "1.4.5"
license = "(MIT and GPL-2.0)"

Output:
licenses = "MIT*"

This is because of this "sub - string" check:

var MIT = /\bMIT\b/;
...
    } else if (MIT.test(str)) {
        return 'MIT*';

Example of affected package.json files:
https://github.com/jqPlot/jqPlot/blob/1.0.9/package.json#L36
https://github.com/gitter-badger/simpler-sidebar/blob/v1.4.5/package.json#L11
https://github.com/maranomynet/formatchange/blob/v2.3.1/package.json#L28