Testsuite: Move forgotten file to correct location

All testsuite stuff is now under ./tests. Consequently,
macro_pickup_tests.cmake should also be moved.
Testsuite: Update a comment
Testsuite: Also use '<>=,' as numdiff separators

This commit addresses issue #38: We have several tests in which numdiff
fails to recognize a number, because the output contains some unknown
delimiters, such as one of "<>=,".
Merge pull request #47 from tamiko/address_testsuite_issues

This pull_request addresses several minor issues with the testsuite: