Improved ISO8601 format for datetimes to support milliseconds, timezones and UTC time.
Fixed failing unit test.
Properly fixed unit tests for all possible timezones now, phew.
Properly fixed tests for WCF datetime format (was using hardcoded value for GMT+1 timezone, oops)
Removed blank line
Merge pull request #1485 from dot-i/finetune-iso8601-format

Improved ISO8601 support