Some improvements (length of matching block) and 
access to the underlying location object
Locations were not correctly copied, now recreates
them and keys them to the prefixed message
Improving the location info for the package info
Provide support for finding a header in the ws/project/sub 
chain including includes
Added test case for finding headers
Added length to the location
Added tests for location stuff
Made the FileLine immutable
Yet another error I don't care about ...