MaxIV NeXus importer (#257)

Get work on new importer out. This is what was done to get to this point:

* start work on NeXus/HDF5 importer for MAX IV

* first working HDF5-MAXIV importer

* rework HDF5 importers for MaxIV

* Got NXazint1d reader done

* save a working snapshot, prior to cleanup

* clean up and test against files

* typo

The importer may get some more review, but should be useful in its current form.

Author: briantoby

GSASII/GSASIIdataGUI.py

@@ -1618,7 +1618,7 @@ def GetDefaultParms(self,rd):
                 else:
                     rd.instmsg = 'default: '+dI.defaultIparm_lbl[res]
                     inst1,inst2 = self.ReadPowderInstprm(dI.defaultIparms[res],bank,rd)
-                    if rd.instdict.get('wave'):
+                    if rd.instdict.get('wave') and 'Lam' in inst1:
                         inst1['Lam'][0] = rd.instdict.get('wave')
                         inst1['Lam'][1] = rd.instdict.get('wave')
                     return [inst1,inst2]

GSASII/GSASIIobj.py

@@ -1433,6 +1433,8 @@ def ReInitialize(self):
         self.instdict = {} # place items here that will be transferred to the instrument parameters
         self.pwdparms = {} # place parameters that are transferred directly to the tree
                            # here (typically from an existing GPX file)
+        self.selections = []
+        self.dnames = []
 ######################################################################
 class ImportSmallAngleData(ImportBaseclass):
     '''Defines a base class for the reading of files with small angle data.