Allow enable_halftomo=auto in nabu config

nabu/resources/nabu_config.py

@@ -283,9 +283,9 @@ nabu_config = {
             "type": "optional", # put "advanced" with default value "edges" ?
         },
         "enable_halftomo": {
-            "default": "0",
-            "help": "Whether to enable half-acquisition",
-            "validator": boolean_validator,
+            "default": "auto",
+            "help": "Whether to enable half-acquisition. Default is auto. You can enable/disable it manually by setting 1 or 0.",
+            "validator": boolean_or_auto_validator,
             "type": "optional",
         },
         "start_x": {

nabu/resources/validators.py

@@ -212,6 +212,14 @@ def boolean_validator(val):
     assert error is None, "Invalid boolean value"
     return res
 
+@validator
+def boolean_or_auto_validator(val):
+    res, error = convert_to_bool(val)
+    if error is not None:
+        assert val.lower() == "auto", "Valid values are 0, 1 and auto"
+        return val
+    return res
+
 @validator
 def float_validator(val):
     val_float, error = convert_to_float(val)