Changing the legup.tcl to use set_project instead of set_board and set_family
set_project sources the characterization file specific to each board. This file
in turn sources the characterization file for the appropriate device family.
set_project also sources the legup.tcl file specific to the project.
Added a new tcl command that sets the output path that is currently used by the
sw-only flow. Soon to be used by the hybrid flow. Also, hopefully to be used by
the hw-only flow.