Allow pipelines to be part of nodes in DataFile API

Fixes the problem Björn encountered in !974 (merged)

In the long-term, we should use the more advanced version from https://git.xfel.eu/dataAnalysis/exdf-tools.

@ahmedk @bjoerns

src/cal_tools/files.py

@@ -107,7 +107,7 @@ class DataFile(h5py.File):
 
     filename_format = '{prefix}-R{run:04d}-{aggregator}-S{sequence:05d}.h5'
     aggregator_pattern = re.compile(r'^[A-Z]{2,}\d{2}$')
-    instrument_source_pattern = re.compile(r'^[\w\/-]+:\w+$')
+    instrument_source_pattern = re.compile(r'^[\w\/-]+:[\w.]+$')
 
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)