Added signal handlers (and placeholder for SEH handlers)

- based on PR 232 (https://github.com/philsquared/Catch/pull/232 - thanks Lukasz Forynski)
- Writes to reporter, so gets all the usual context, but then exits directly (since the stack cannot be resumed) so no summary
- On Windows does nothing, as yet.

include/reporters/catch_reporter_compact.hpp

@@ -109,6 +109,13 @@ namespace Catch {
                         printExpressionWas();
                         printRemainingMessages();
                         break;
+                    case ResultWas::FatalErrorCondition:
+                        printResultType( Colour::Error, failedString() );
+                        printIssue( "fatal error condition with message:" );
+                        printMessage();
+                        printExpressionWas();
+                        printRemainingMessages();
+                        break;
                     case ResultWas::DidntThrowException:
                         printResultType( Colour::Error, failedString() );
                         printIssue( "expected exception, got none" );