ECfilter enhancement, option to process HTTP 301,302 lines in logfiles

When processing EZproxy SPU log files, resources with HTTP 301 or 302 may represent valid anonymous resource usage. If EZproxy is configured with ExcludeIP ranges, it will not proxy requests from those IPs, instead sending the request directly to the vendor.  However, those actions are still logged in [`LogSPU`](http://oclc.org/support/services/ezproxy/documentation/cfg/logspu.en.html), and may be used to calculate the overall proxied and non-proxied usage of the vendor's resource.

This pull request adds 2 features:

- [7db3e9a](https://github.com/UMNLibraries/ezpaarse/commit/7db3e9af1fac695ff5651dec46edca926295821c) creates a log file for lines discarded by the `ecfilter.isValid()` check in `lines-filtered-ecs.log` (I added this to discover why our logs for local, non-proxied resources were not being processed by ezPAARSE)
- [4de27fd](https://github.com/UMNLibraries/ezpaarse/commit/4de27fd16e2453e5b2eec33e71c9db5c0e2018db) adds a header option `ezPAARSE-Filter-Redirects` which if set `false` causes ezPAARSE to process the 301, 302 redirect lines.  The default is `true` to filter them in `ecfilter.isValid()` - the current behavior.
- [502cf4e](https://github.com/UMNLibraries/ezpaarse/commit/502cf4e1455206bb25345d65f3bf3272326cf6ee) adds a mention `ezPAARSE-Filter-Redirects` to `doc/routes.md`. My French is inadequate, however. I have written it in English.

Tests are included for both features. Thank you for your consideration.