pyang-2.4.0

     #690 - stop uses expanding if import circular dependency exists
     #685 - report errors in sample-xml-skeleton
     #683 - fix sample-xml-skeleton unknown namespace crash
     #681 - newline fix in tree plugin
     #678 - deviate replace regression
     #673 - fix unreasonable the case node status
     #669 - type validator crashes on valid range restriction
     #665 - output status value in flatten plugin
     #661 - sort output for flatten plugin
     #660 - add module:prefix:node output for flatten plugin