E3-1589: Fix truncated error logs

In EPICS base, the errorlog functionality is initialised with a default maximum error log size of 256. This means that error messages longer than that size show as `<>´, which means that we miss a number of important messages, in particular error messages due to missing symbols from shared libraries when they are loaded.

errlogInit unfortunately is a bit of a singleton; it can only be called a single time, and it is called when we load require the very first time.