It didn't work with CIDR format IP addresses. I cannabilized the
code from canShowDebug and refactored it into its own method,
canShowBasedOnIP. Both canShowDebug and canShowPerformanceIndicators call this.
Updated the docs for the debugIp setting to note that it's used for both
showDebug and showPerformanceIndicators.
Added about 20 more tests to ErrorHandler.t. Only the two hard methods are
left, fatal (which closes the session at the end) and showDebug, which is
validating a ton of output.
a0d2326f9c