Fix for Issue #148: All dates should be independent of locale settings

[johnerikhalse]

Updates all creations of java.text.SimpleDateFormat to explicitly setting locale to ENGLISH.

Two unit tests will break until pull request iipc/webarchive-commons#22 is applied.

Someone should double check for side effects before applying this.

[kris-sigur]

I can't see any reason not to merge this.
@anjackson unless you object, I'll merge this in before the monthly call later this week.

[anjackson]

Looks good to me.

[kris-sigur]

Looks like this has caused the travis build to fail. The root cause is that the test is triggering the generation of a date in WarcResource.java line 135 which uses DateUtils from webarchive-commons`. That in turn does not set the Locale correctly.

[johnerikhalse]

As I mentioned in the initial comment, the pull request is dependent on the pull request in webarchive commons (iipc/webarchive-commons#22). For the build to succeed, a release of webarchive-commons has to be made and then update openwayback to depend on this release.