Add reordering for aoflagger (RAP-129)

In order to avoid a huge main memory usage of the aoflagger step, the user should be enabled to make use of the indirect-read (aka reorder) mode of aoflagger. See RAP-129

docs/source/calibrator.rst

@@ -278,7 +278,7 @@ A comprehensive explanation of the baseline selection syntax can be found `here`
 
 - ``max_dppp_threads``: number of threads per process for DP3 (default: 10)
 - ``memoryperc``: maximum of memory used for aoflagger in raw_flagging mode in percent (default: 20)
-- ``aoflag_reorder``: will reorder the measurement set before running aoflagger
+- ``aoflag_reorder``: make aoflagger reorder the measurement set before running the detection. This prevents that aoflagger will use its memory reading mode, which is faster but uses more memory (see the `AOFlagger manual`_`)
 
 **Parameters you may want to adjust**
 
@@ -296,3 +296,4 @@ A comprehensive explanation of the baseline selection syntax can be found `here`
 
 .. _here: https://www.astron.nl/lofarwiki/doku.php?id=public:user_software:documentation:ndppp#description_of_baseline_selection_parameters
 .. _AOFlagger: https://gitlab.com/aroffringa/aoflagger.git
+.. _AOFlagger manual: https://aoflagger.readthedocs.io/en/latest/using_aoflagger.html
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