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.