Use rules defined in SBT module within a multi-module build

[cchantep]

Currently it's not possible to use rules defined in a SBT modules in other modules of the same multi-modules project without publishing, aka not possible to use inter-module dependencies (e.g. dependsOn).

Local rules are not sufficient neither when rules are to be used accross several sibling modules, nor when the rules module itself needs specific libraryDependencies.