Adding the ability to modify the default onerror behaviour

[hodgestar]

It would be nice if we could just set onerror once. A patch from Walter.

[hodgestar]

Walter's patch.

[hodgestar]

Notes from Walter:

Adding the ability to modify the default onerror property in the <build> element. If not specified, the behavior is unchanged; by default any step failure will result in the build failing and stopping.

Added a new continue onerror specification-- it's similar to ignore except the results of continue steps are counted in the overall build status (in ignore they're ignored.)

You'll need to upgrade both your master and slaves if you wish to use the <build> element override or the new continue value.

Will update ​http://bitten.edgewall.org/wiki/Documentation/recipes.html.

[wbell]

Updated patch with some feedback.

[wbell]

Fixed by [832]