* Replace custom type names with _doc in REST examples.
* Avoid using two mapping types in the percolator docs.
* Rename doc -> _doc in the main repository README.
* Also replace some custom type names in the HLRC docs.
This commit moves the definition of domainSplit into java and exposes it
as a painless whitelist extension. The method also no longer needs
params, and version which ignores params is added and deprecated.