Feature/cors filter

Based on http://www.w3.org/TR/cors/
The filter is called at the earliest possible point
Only works on preflight requests.
Created as a ConfigurationFactory and hence each host will have its own configurations
Junits available for the util class 
Since the filter had just string compares , have not created a junit.
Not necessary to change, but im a big fan of `StringUtils.isNotBlank(originStr)` .. its easy to read and null friendly