Revert "it's possible to sort using a function, in that case ActiveScaffold can't get the column"
Revert "it's possible to sort using a function, in that case ActiveScaffold can't get the column"

This reverts commit d939b1d40cff5cb82f28ec84433ccd2d61506edc.

AlbertoBarrago/active_scaffold,budree/active_scaffold,activescaffold/active_scaffold,budree/active_scaffold,AlbertoBarrago/active_scaffold,mallikarjunayaddala/active_scaffold,mallikarjunayaddala/active_scaffold,AlbertoBarrago/active_scaffold,activescaffold/active_scaffold,activescaffold/active_scaffold,budree/active_scaffold,mallikarjunayaddala/active_scaffold