add missing generation of z3.z3 for pydoc and add some explanations t…

…o logging function declaration

doc/mk_api_doc.py

@@ -335,6 +335,7 @@ def doc_path(path):
 
         for modulename in (
                 'z3',
+                'z3.z3',
                 'z3.z3consts',
                 'z3.z3core',
                 'z3.z3num',

src/api/ml/z3.mli

@@ -49,6 +49,13 @@ type context
 val mk_context : (string * string) list -> context
 
 (** Interaction logging for Z3
+    Interaction logs are used to record calls into the API into a text file.
+    The text file can be replayed using z3. It has to be the same version of z3
+    to ensure that low level codes emitted in a log are compatible with the
+    version of z3 replaying the log. The file suffix ".log" is understood
+    by z3 as the format of the file being an interaction log. You can use the
+    optional comman-line parameter "-log" to force z3 to treat an input file
+    as an interaction log.
     Note that this is a global, static log and if multiple Context
     objects are created, it logs the interaction with all of them. *)
 module Log :