rename a number of internal and externally visible variables to use the fixture name

rather than funcargs.  Introduce .funcargnames compatibility attribute for backward compat.

doc/en/example/assertion/failure_demo.py

@@ -15,7 +15,7 @@ def test_generative(param1, param2):
     assert param1 * 2 < param2
 
 def pytest_generate_tests(metafunc):
-    if 'param1' in metafunc.funcargnames:
+    if 'param1' in metafunc.fixturenames:
         metafunc.addcall(funcargs=dict(param1=3, param2=6))
 
 class TestFailing(object):

doc/en/example/attic.txt

@@ -13,9 +13,9 @@ example: specifying and selecting acceptance tests
             help="run (slow) acceptance tests")
 
     def pytest_funcarg__accept(request):
-        return AcceptFuncarg(request)
+        return AcceptFixture(request)
 
-    class AcceptFuncarg:
+    class AcceptFixture:
         def __init__(self, request):
             if not request.config.option.acceptance:
                 pytest.skip("specify -A to run acceptance tests")
@@ -39,7 +39,7 @@ and the actual test function example:
 If you run this test without specifying a command line option
 the test will get skipped with an appropriate message. Otherwise
 you can start to add convenience and test support methods
-to your AcceptFuncarg and drive running of tools or
+to your AcceptFixture and drive running of tools or
 applications and provide ways to do assertions about
 the output.
 

doc/en/example/parametrize.txt

@@ -84,7 +84,7 @@ Now we add a test configuration like this::
             help="run all combinations")
 
     def pytest_generate_tests(metafunc):
-        if 'param1' in metafunc.funcargnames:
+        if 'param1' in metafunc.fixturenames:
             if metafunc.config.option.all:
                 end = 5
             else:
@@ -213,7 +213,7 @@ creates a database object for the actual test invocations::
     # content of conftest.py
 
     def pytest_generate_tests(metafunc):
-        if 'db' in metafunc.funcargnames:
+        if 'db' in metafunc.fixturenames:
             metafunc.parametrize("db", ['d1', 'd2'], indirect=True)
 
     class DB1: