Fixed test failures and errors caused in tests using the runkit extension

Fixed:

1. errors pertaining to runkit extension in tests under
PMA_headerLocation_test.php
2. errors pertaining to runkit extension in tests under
PMA_whichCrlf_test.php
3. failed test: testSendHeaderLocationWithoutSidWithIis()
Added another assertion for testSendHeaderLocationWithoutSidWithIis

Also fixed the syntax for getting user defined constants as previous
one was failing the Travid build
Merge pull request #192 from ayushchd/unitTesting

Fixed test failures and errors caused in tests using the runkit extension