Fixed issue #45

event propagation was causing inconsistent behavior with confirm click
directive. eliminated the added propagation of row-level-click by moving
to column-level-click. and, reworked the remaining propagation pieces.
added bootstrap garbage collection

invoke bs-api hide to cleanup all modal dom manipulations, eg backdrop,
scrollremove, et al.
Fixed issue #47

disallowed more than 4 digits in ssn fields.
switched to pattern with text instead of min/max with number, because
latter allows fewer than 4 digits, eg 1 is allowed in lieu of 0001.
using in tandem w/ ng-pattern because angular does not honor the html5
native attr.