MXS-1356: Allow tee filter to be disabled at runtime

Disabling the tee filter at runtime is desirable for cases where the
branched service is not always needed. Migrations and pre-production
setups are one where changes to the branched service are expected and
splitting the queries would result in an error.

Documentation/Filters/Tee-Filter.md

@@ -99,6 +99,23 @@ sessions that are connected using this username are replicated.
 user=john
 ```
 
+## Module commands
+
+Read [Module Commands](../Reference/Module-Commands.md) documentation for
+details about module commands.
+
+The tee filter supports the following module commands.
+
+### `tee disable [FILTER]`
+
+This commmad disables a tee filter instance. A disabled tee filter will not send
+any queries to the target service.
+
+### `tee enable [FILTER]`
+
+Enable a disabled tee filter. This resumes the sending of queries to the target
+service.
+
 ## Examples
 
 ### Example 1 - Replicate all inserts into the orders table

Documentation/Release-Notes/MaxScale-2.2.0-Release-Notes.md

@@ -59,6 +59,13 @@ The `match` and `exclude` parameters were changed to use PCRE2 syntax for the
 regular expressions. The regular expression should be enclosed by slashes
 e.g. `match=/select.*from.*test/`.
 
+A tee filter instance can be disabled with the new `tee disable [FILTER]` and
+`tee enable [FILTER]` module commands. Refer to the
+[module command documentation](../Reference/Module-Commands.md) for more
+details on module commands and the
+[Tee Filter documentation](../Filters/Tee-Filter.md) for details on the tee
+filter specific commands.
+
 ### Dbfwfilter
 
 The `function` type rule will now match a query that does not use a function