Bug 14395: Add new syspref NoRenewalBeforePrecision

Bug 14395: Add new syspref NoRenewalBeforePrecision

Currently the 'NoRenwalBefore' setting is always based on the exact
DateTime of the due date. This patch introduces a new global syspref for
choosing if 'NoRenewalBefore' should instead be calculated based on date
only. This is only relevant for loans caluclated in days. Hourly loans
are not affected.

To test:

1) Apply bug 14101, then apply this patch.

2) Run installer/data/mysql/updatedatabase.pl

3) Confirm that a new syspref NoRenewalBeforePrecision is available
   in administration. It should let you choose between 'date' (default)
   and 'exact time'.

Sponsored-by: Hochschule für Gesundheit (hsg), Germany
Signed-off-by: Jesse Weaver <jweaver@bywatersolutions.com>