test: Add known-broken test for empty author name

We test for whether a quoted empty email address

    "" <address@example.com>

will show up as the address, instead of the empty string. This is
marked as known-broken, since the current behavior is to use the empty
string.

This is a new test file, since handling of unusual email addresses
doesn't seem to fit well in any of our existing tests.

Signed-off-by: Jesse Rosenthal <jrosenthal@jhu.edu>
lib: Use email address instead of empty real name.

Currently, if a From-header is of the form:

    "" <address@example.com>

the empty string will be treated as a valid real-name, and the entry
in the search results will be empty.

The new behavior here is that we treat an empty real-name field as if
it were null, so that the email address will be used in the search
results instead.

Signed-off-by: Jesse Rosenthal <jrosenthal@jhu.edu>