SCTK: Enhance the ignore_patterns option to exclude "scopes" as well as specific file paths

[DennisClark]

Enhance the ignore_patterns scan option to exclude "scopes" as well as specific file paths

Benefit:
takes advantage of scope definitions to streamline a scan

[pombredanne]

I think that we should not mix patterns to ignore files and list of dependency scopes or packages to ignore. These should be separate sections of the config file; and the patterns syntax and the code to implement them is completely different: we have globs for paths and plain combos of package type/scope names for the scopes.
Also for now I think this issue is best in ScanCode.io as there is scancode-config.yml file support in SCTK for now, only in SCIO.

[pombredanne]

@AyanSinhaMahapatra I think this is done, is it?