Make default behavior to stop all analysis on first exception thrown

[jafingerhut]

The current behavior is to stop analyzing a single file if an exception is thrown, but to go on and try to analyze other namespaces. However, when an exception is thrown on one namespace, no further analysis and eval is done for any later forms in the file. Thus if there are Vars defined later in that file with the first exception, it can cause undefined Var exceptions during analysis of later namespaces that assume that Var is defined, which is misleading.

It still might be useful for my own development testing to have an option to operate as it currently does, because then output from one crucible run to the next might be more consistent.

[jafingerhut]

This enhancement was first released as part of Eastwood version 0.1.5