Reshape 0.7.1

 * default to outputting data.frames

 * now compatible with R 2.4
 * added fill argument to cast, to specify what value should be used for structural missings
 * fun.aggregate will always be applied if specified, even if no aggregation occurs
 * margins now work for non-aggregated data
 * cast will now accepted a list of functions for fun.aggregate
 * very long formulas will now work in cast
 * fixed bug in rbind.fill
 * should be able to melt any cast form