FRDA-175: Add text anchors around Speaker sent in via the solr params.

This change causes the speaker string to be sent into solr amended with "aaa"
and appended with "zzz". The purpose is to make sure that speeches where a
speaker is mentioned do not show up in searches as being by that speaker.
Merge pull request #5 from sul-dlss/FRDA-175

FRDA-175: Add text anchors around Speaker sent in via the solr params.