* register map contained always the same instances for each kind
* core problem: the new ... generators are implicitly converted to const
* fixed by adding random Gen element to both generators

* new scheme: chisel.axi is the main package
* chisel.axi.Axi4 contains the full axi defs
* chisel.axi.Axi4Lite contains the lite defs
* chisel.axi.axi4 contains full Axi4 impls
* chisel.axi.axi4lite contains lite impls
* same applies for the generators, matching structure

* moved DataWidth from top axi to Axi4/Axi4Lite objects
* cleaned generators, adopted new naming structure
* implemented generators for arbitrary register files
* master actions improved, simpler constructors
* master actions can be automatically generated from register file
* need to clean up the namespaces etc. - gotten really messy