Move version tests in mapreduce suite in under ignore blocks

Moves the Python and Perl version tests in under ignore blocks to
make the test less fragile. Testing for specific versions is not
ideal, if this is to be kept as a real test it should be rewritten
to look for interpreters satisfying minimum version requirements
rather then exact (although the value of that can be argued as
well). Keep the version output in the test though since it can be
good information when debugging where access is limited to the
regression.diffs file. Also fix a trivial typo in a comment while
in there.

src/test/regress/input/mapred.source

@@ -26,7 +26,7 @@ create language plpythonu;
 select * from pg_pltemplate;
 select lanname, lanispl, lanpltrusted from pg_language;
 
--- Check enviornment variables that should have been set by greenplum_path.sh
+-- Check environment variables that should have been set by greenplum_path.sh
 --
 -- 1) We need to check these on all segments and on the master.
 -- 2) We do this via external table rather than perl/python in case it is part
@@ -52,6 +52,7 @@ SELECT * FROM env WHERE var in (
 
 -- end_ignore
 
+-- start_ignore
 --
 -- Some checks to verify what versions of perl/python we have.
 -- If everything has been configured correctly this should be constant
@@ -78,7 +79,6 @@ CREATE OR REPLACE FUNCTION perl_version() returns text as $$
 return "Perl $]"
 $$ language plperlu NO SQL;
 
--- ignore
 SELECT perl_version() FROM env GROUP BY perl_version;
 
 
@@ -86,7 +86,6 @@ SELECT perl_version() FROM env GROUP BY perl_version;
 -- The following two checks need to be put into big ignore blocks
 -- because paths can be of differing lengths
 --
--- start_ignore
 
 CREATE OR REPLACE FUNCTION python_path() returns text as $$
 import sys

src/test/regress/output/mapred.source

@@ -42,7 +42,7 @@ select lanname, lanispl, lanpltrusted from pg_language;
  plpythonu | t       | f
 (6 rows)
 
--- Check enviornment variables that should have been set by greenplum_path.sh
+-- Check environment variables that should have been set by greenplum_path.sh
 --
 -- 1) We need to check these on all segments and on the master.
 -- 2) We do this via external table rather than perl/python in case it is part
@@ -79,6 +79,7 @@ SELECT * FROM env WHERE var in (
 (10 rows)
 
 -- end_ignore
+-- start_ignore
 --
 -- Some checks to verify what versions of perl/python we have.
 -- If everything has been configured correctly this should be constant
@@ -107,7 +108,6 @@ SELECT python_version() FROM env GROUP BY python_version;
 CREATE OR REPLACE FUNCTION perl_version() returns text as $$
 return "Perl $]"
 $$ language plperlu NO SQL;
--- ignore
 SELECT perl_version() FROM env GROUP BY perl_version;
  perl_version  
 ---------------
@@ -118,7 +118,6 @@ SELECT perl_version() FROM env GROUP BY perl_version;
 -- The following two checks need to be put into big ignore blocks
 -- because paths can be of differing lengths
 --
--- start_ignore
 CREATE OR REPLACE FUNCTION python_path() returns text as $$
 import sys
 return sys.path[0]