add EXEEXT to test_vars
add EXEEXT to test_vars

Some scripts that run unit tests assume that the compiled unit test
programs do not have an extension, which is not always true.
Adding in the EXEEXT variable, which lists what the extension, if
any, is.

git-svn-id: d023f1085a36f7a677188d00334e37d38ffecf51@754 64e312b2-a51f-0410-8e61-82d0ca0eb02a

brarcher/check,libcheck/check,libcheck/check,krichter722/check,9fcc/check,libcheck/check,brarcher/check,brarcher/check,krichter722/check,krichter722/check,krichter722/check,9fcc/check,9fcc/check,brarcher/check,libcheck/check,9fcc/check,krichter722/check,libcheck/check,brarcher/check,9fcc/check