Code cleanup: remove param2 from langopts and rename keyword option in language files.

- param2[] is only used to set a second value to LOPT_BRACKET_PAUSE. It is simpler
to have two values in param[] instead. This simplifies the codebase.

- Instead of setting "option bracket X Y" in language files, use
keywords "brackets X" and "bracketsAnnounced Y" instead to follow the
naming convention of other keywords.

- Add missing documentation to docs/voices.md.

docs/voices.md

@@ -21,6 +21,8 @@
   - [speed](#speed)
   - [words](#words)
 - [Language Attributes](#language-attributes)
+  - [brackets](#brackets)
+  - [bracketsAnnounced](#bracketsAnnounced)
   - [phonemes](#phonemes)
   - [dictionary](#dictionary)
   - [dictrules](#dictrules)
@@ -335,6 +337,22 @@ vowel and the next start with a vowel.
 
 ## Language Attributes
 
+### brackets
+
+	brackets <value>
+
+Default value: 4
+
+Increases the pause when reading brackets. Example: "Pause (with brackets)".
+
+### bracketsAnnounced
+
+	bracketsAnnounced <value>
+
+Default value: 2
+
+Increases the pause when reading brackets when --punct is set to read bracket names. Example: "Pause (with brackets)".
+
 ### phonemes
 
 	phonemes <name>