Dsc 807

Hi Shaun,

This request includes parsing of date range for collection work and component works for indexing.  It also included several additional EAD fields which was missed previously.  Could you please review these changes?

Thanks,
Shuang
How about just rethrowing as RuntimeException immediately? Then no need for the error variable. We're also discarding the exception object which will make debugging more difficult. Exceptions can take another exception as their cause, as the second argument to the constructor:
```java
throw new RuntimeException("Failed to parse expr : " + expr, e);
```