Initial implementation for tracing: Added macros BBXLOG_TRACE_METHODBEGIN and BBXLOG_TRACE_METHODEND.
1) Added additional support for tracing so that the BBXMessageDetails now has an attribute to determine the type of message, i.e. TRACE or LOG.
2) Added conditional alerting, i.e. the level at which an alert view will be displayed - The default is currently set for FATAL.