Add explicit identification of the master authority record when merging

Add explicit identification of the master authority record when merging

We now generate a table with the first cell containing either "Master"
(indicating the record into which the other records will be merged) and
or "Target" (indicating that the record will be merged into the master.

This also adds a horizontal rule to delineate between the form buttons
at the top, and adds borders to provide more clarity between the mergebox
contents.

git-svn-id: svn://svn.open-ils.org/ILS/trunk@17343 dcc99617-32d9-48b4-a31d-7c20da2025e4