Link code references in low-level API docstrings

[oubiwann]

Originally filed at clojang/clojang#14.

Right now the docstrings in the jiface API has the following issues:

• Some object names are just code text instead of being links to the documentation for that object
• Some linked code points to the javadocs, some to the low-level API docs
• parameters and return values are not discussed

These all need to be fixed:

• Ensure all code text points to the low-level documentation for the given namespace or function
• Ensure that the JInterface objects are referenced only when saying what is wrapped (and then, link to the javadocs)
• Ensure that docstrings have notes about the return value and the possible types for function arguments)