Since chisel now depends on firrtl, we need a way for super projects (i.e., rocket-chip) to control the actual firrtl package used by chisel.

No more need for e.g.

    new Bundle {
      def foo(dummy: Int): Data
    }

as now you can write

    new Bundle {
      def foo: Data
    }

This also removes code duplication with Module.

h/t @sdtwigg 

* FixedPoint number support for chisel3
FixedPoint numbers have a width and a binary position
Either, neither or both maybe inferred.
Firrtl will convert these to SInts during lowering passes

* Fixes based on Jack's comments on PR #328

* Add experimental warning to FixedPoint class and object

* Fixed comment per Adam's comment on PR #328

Add a cloneType method to QueueIO

Tobits deprecation

This causes Verilator tests to compile faster and use less memory

Implement a standardized execution scheme for chisel

Provide support for chisel options
Provide support for firrtl options when called as part of chisel compile
provide command line support the above options via scopt
provide and execution result class that can be used when chisel3 is part
of some externally controlled toolchain

Candidate fix for #245

This reverts commit 10f17011.

Buildinfo

This reverts commit 3ea7faaa, reversing
changes made to 7aea39d4.

Update chisel-testers before commiting this change (deleting EnqIO/DeqIO).

Remove EnqIO, DeqIO - #308

Generate a better error message for missing IO() wrapper - fix #305

clone firrtlDirection when cloning - Issue #306

Use "chisel3" as sbt project name.

Add Cookbook tests

Update Driver: Check the simulation exit code #281

Merge with master and support checking for failure with an explicit assertion message.

TransitName comment change.

Update @sdtwigg's PR #199 - Add Assert Data.

This was originally mixed in with #199, Add Assert Data.

Update to current sbt resolver idiom.

Give <> and := legacy behavior in compatibility mode