add and document new parser.addini(name, description) method to describe

ini-values. Also document the parser object with its public methods.

--HG--
branch : trunk

testing/test_parseopt.py

@@ -1,5 +1,6 @@
 import py
 from pytest.plugin import config as parseopt
+from textwrap import dedent
 
 class TestParser:
     def test_no_help_by_default(self, capsys):
@@ -100,6 +101,18 @@ class TestParser:
         assert option.hello == "world"
         assert option.this == 42
 
+    def test_parser_addini(self, tmpdir):
+        parser = parseopt.Parser()
+        parser.addini("myname", "my new ini value")
+        cfg = py.iniconfig.IniConfig("tox.ini", dedent("""
+            [pytest]
+            myname=hello
+        """))['pytest']
+        class option:
+            pass
+        parser.setfromini(cfg, option)
+        assert option.myname == "hello"
+
 @py.test.mark.skipif("sys.version_info < (2,5)")
 def test_addoption_parser_epilog(testdir):
     testdir.makeconftest("""