analysis: add some references, doc.

Author: williballenthin

idb/analysis.py

@@ -396,11 +396,13 @@ def inner(db):
 ])
 
 
+# see `scripts/dump_user.py` for intepretation.
 OriginalUser = Analysis('$ original user', [
     Field('data', 'S', 0, bytes),
 ])
 
 
+# see `scripts/dump_user.py` for intepretation.
 User = Analysis('$ user1', [
     Field('data', 'S', 0, bytes),
 ])