Patch from Dan Wells:

Patch from Dan Wells:

I will start with the changes which I think are straightforward.  First, textual_holdings are sometimes used to augment the generated_coverage and at other times should completely replace it (generally when the holdings statement is too complex to be easily generated or has more detail than we care about).  The 'show_generated' flag in each summary table is a simple means of indicating which type of display we want.  Second, 'summary_method' will be consulted when generating the 'generated_coverage' fields, and tells us how any attached MFHD records (SREs) should be treated for this distribution in relation to the new structured data (attempt to merge the data, generate display data from both separately, or generate based on one or the other only).

The changes to serial.caption_and_pattern are not as straightforward, but I think they are justifiable.  Any given caption/pattern is only valid for a certain period of time (i.e. until it changes).  As it stands, we can infer the start and end dates of a caption/pattern only by consulting the attached issuances.  In practice this means retrieving and sorting sometimes hundreds of issuances to provide for the sorted display of just a few caption/patterns.  As I work with these objects more, I am simply often wishing for a more convenient access point to this important data.  This also means that the 'active' flag is redundant (caption/patterns with end_date-s are not active), but we need to get end_date in place before we can start removing the 'active' flag from the code.

git-svn-id: svn://svn.open-ils.org/ILS/trunk@17715 dcc99617-32d9-48b4-a31d-7c20da2025e4