Unit test failures because sys_get_temp_dir() doesn't always return directory name with trailing slash
php function sys_get_temp_dir() usually returns something like '/tmp/', but on some systems the trailing slash is missing (for me: a debian stable box, self compiled php 5.3.2, running as cgi). This leads to failing tests, eg. in Cache\Backend\PdoBackendTest
This could be easily fixed by always adding a slash (see attached patch), but leads to double slashes if the method returns with trailing slash.
Maybe it would be better to add / use some wrapper method to add the slash if it's missing?