Provide URI to File-System Path Transalation

[tntim96]

Implement a generic solution for the scenario where, in proxy mode, a custom loader implementation results in the URI path not matching the file-system path (relative to the document-root). The translated path should, when appended to the document-root, match the file on the file-system. This translation is needed so that if the '--include-unloaded-js' option is present, JSCover will be able to recognize files on the file-system that have already been instrumented and therefore included in the report.

[tntim96]

The solution for simple cases can be handled by providing two switches:

1. --uri-to-file-matcher=REG specify a regular expression matcher with optional capture groups
2. --uri-to-file-replace=REP specify a regular expression replacement with optional captured groups

An example to convert '/exclude/include/code.js' to '/include/code.js' would be: --uri-to-file-matcher=/exclude(.*) --uri-to-file-replace=$1

More difficult transformations can be handled by providing a JavaScript function in a file. This will be included if required by the community, but won't be solved as part of this log.