move verifyAllMuxes before width inference(issue #335)

I moved verifyAllMuxes before width inference. Now it will inform like:

[info] [0.037] // COMPILING class TutorialExamples.TestFloating(0)
[info] [0.045] giving names
[info] [0.049] executing custom transforms
[error]: NO DEFAULT SPECIFIED FOR WIRE: /*io_o_value in class TutorialExamples.TestFloating*/ Chisel.UInt(OUTPUT, width=64, connect to 1 inputs: (T0[Chisel.Mux] in TutorialExamples.TestFloating)) in component class TutorialExamples.TestFloating
Re-running Chisel in debug mode to obtain erroneous line numbers...
[info] [0.004] // COMPILING class TutorialExamples.TestFloating(0)
[info] [0.004] giving names
[info] [0.004] executing custom transforms
[error] TestFloating.scala:7: NO DEFAULT SPECIFIED FOR WIRE: /*io_o_value in class TutorialExamples.TestFloating*/ Chisel.UInt(OUTPUT, width=64, connect to 1 inputs: (T0[Chisel.Mux] in TutorialExamples.TestFloating)) in component class TutorialExamples.TestFloating in class TutorialExamples.TestFloating
[error] (run-main) java.lang.IllegalStateException: CODE HAS 1 ERRORS and 0 WARNINGS
java.lang.IllegalStateException: CODE HAS 1 ERRORS and 0 WARNINGS
	at Chisel.ChiselError$.checkpoint(ChiselError.scala:128)
	at Chisel.Backend.elaborate(Backend.scala:826)
	at Chisel.VerilogBackend.elaborate(Verilog.scala:1038)
	at Chisel.Driver$.execute(Driver.scala:93)
	at Chisel.Driver$.apply(Driver.scala:40)
	at Chisel.Driver$.apply(Driver.scala:45)
	at Chisel.chiselMain$.apply(hcl.scala:59)
	at TutorialExamples.TutorialExamples$.main(examples.scala:96)
	at TutorialExamples.TutorialExamples.main(examples.scala)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:606)
[trace] Stack trace suppressed: run last tests/compile:run for the full output.
java.lang.RuntimeException: Nonzero exit code: 1
	at scala.sys.package$.error(package.scala:27)
[trace] Stack trace suppressed: run last tests/compile:run for the full output.
[error] (tests/compile:run) Nonzero exit code: 1
[error] Total time: 51 s, completed Nov 21, 2014 1:47:25 PM