Added pruneSteps as a function.
Inital implementation of raxRolesMask transform.
Added maskRaxRoles403 option and added to CLI.
Whoops, need to make sure that @notMatch is sorted.
Whoops, failed to take account @next in header join opt.
Move rax:roles header checks above URI checks.
Whoops, merge next links correctly.
Minor fixes in merge operation.
Initial 403 mask tests.