Build: Skip the required files if they are excluded.

[jorix]

There are some source files that are only required if default values are used, for example:

• Using new OpenLayers.Map(..., {panMethod: null, ...}); then OpenLayers/Tween.js is not required
• Using new OpenLayers.Control.LayerSwitcher({roundedCorner: false}); then Rico/Corner.js is not required

But it is not possible to exclude these files using the [exclude] clause in the configuration files. The file is always included if file name is in @requires into an other source file.

The patch proposes changes in mergejs.py to take into account the [exclude] clause to exclude also the required files.

[jorix]

This solution does not work for directory exclusion. I'll work some more...

[jorix]

3496.patch works (I had a problem when combined with another patch that I am studying)

I have prepared 3496.1.patch that creates a cache for _getRequirement, but two patches give the same results.

Please review.

[jorix]

Please review:  https://github.com/openlayers/openlayers/pull/135

[tschaub]

In w/  https://github.com/openlayers/openlayers/commit/a5f4daa747744fc9fe92d603ff67f2f037aa4b8e. Thanks @jorix.