Handle (.) special form
Eagerly walk over remainder of dot form

For some reason, without this, macroexpansion of core's (defn agent)
form fails with

    CompilerException java.lang.RuntimeException: Unable to resolve symbol:
    opts in this context,
    compiling:(/tmp/form-init808598376933005585.clj:1:1338)

...but only if you require riddley from a different project.  I was
symlinking to it in the lein checkouts/ directory, too, which may or may
not be relevant.
Eagerly walk over dot args too.

Maybe these maps need to be evaluatued eagerly because the evaluation
context has gone by the time they are evaluated lazily.  For instance,
without this commit, the following form fails with "CompilerException
java.lang.RuntimeException: Unable to resolve symbol: rename in this
context":

    (macroexpand-all
    '(defn refer
      []
        (let [rename {} sym 1]
          (. *ns* (refer (or (rename sym) sym))))))
Merge pull request #5 from coventry/dot-handler

Handle (.) special form