Patch #1080684: typo repair. Thanks George Yoshida!

- Doc/lib/libbase64.tex
s/algorith/algorithm

- Doc/lib/libpickle.tex
s/interchangable/interchangeable

- Doc/lib/libxmlrpclib.tex
s/{_cmp__}/{__cmp__}

leading underscore needs to be double, not single.

- Doc/ref/ref6.tex
0/1 => False/True
diff --git a/Doc/lib/libpickle.tex b/Doc/lib/libpickle.tex
index 4013432..cf526a0 100644
--- a/Doc/lib/libpickle.tex
+++ b/Doc/lib/libpickle.tex
@@ -825,7 +825,7 @@
 
 There are additional minor differences in API between \module{cPickle}
 and \module{pickle}, however for most applications, they are
-interchangable.  More documentation is provided in the
+interchangeable.  More documentation is provided in the
 \module{pickle} module documentation, which
 includes a list of the documented differences.