Removed special case in buildExpWithDotteds() that returned an
AVariableExp when the list of dotted identifiers was empty; it now
always returns a unresolved path.  This is in the context of building an
operation call in the leadingIdAction rule.  Related to #209.
[skip ci]
close #209 I can confirm that this bug is fixed. This commit also addes extra tests and error reporting for pair.#1.op() invalid use of # in designators