bug 2000 - added several circ rules tables (DB rev 090)

bug 2000 - added several circ rules tables (DB rev 090)

The first new table is branch_borrower_circ_rules.

This table is used to store circulation rule attributes
that apply to a combination of patron category and branch
across all item types.  The one attribute defined is
maxissueqty, which sets the maximum number of loans
that a patron of a given category can take out at a given
branch.

Note that branch_borrower_circ_rules is for attributes
that apply across all item types.  This means that
issuingrules.maxissueqty has a different meaning: it is
the maximum number of loans per branch, category, and item type;
if issuingrules.itemtype is '*', that is a *default*
circulation rule used if no more specific rule is found.

The new table will allow the implementation of total
loan limit across item types without making the wildcard
'*' in issuingrules ambiguous.  Specifically, if branchcode,
categorycode, or itemtype is issuingrules is '*', that will now
always mean a loan rule to be applied if a more specific rule cannot be found.
Setting issuingrules.itemtype to '*' will no longer mean
to set a total limit across item types for maxissueqty.

The remaining new tables are used to store default
rules for the default branch, the default patron category,
or both:

default_branch_circ_rules - for a given branch, specify
the rule to apply if no more specific rule on
branch and patron category is found (i.e. patron category is default)

default_borrower_circ_rules - for a given patron category,
specify the rule to apply if no more specific rule
on branch patron category is found (i.e., branch is default)

default_circ_rules - global default if no more specify rule
on patron category and branch is available.  Note that this
table is constructed so that it can have at most
one row.

Signed-off-by: Joshua Ferraro <jmf@liblime.com>