use empty string so TempDir uses the OS's temp dir automatically (Closes #2117)
fix rm -v
Make sure to close the network allocators
replace panic by log.Fatal in tests
Merge pull request #2145 from dotcloud/remove-panic-test

* Runtime: replace panic by log.Fatal in tests
Merge pull request #2133 from dotcloud/improve_tests

Make sure to close the network allocators
Merge pull request #2119 from SvenDowideit/2117-hardcoded-tmp-dir

use empty string so TempDir uses the OS's temp dir automatically (Closes...
Merge pull request #2125 from dotcloud/2099_rm-v_fix

- Runtime: fix `docker rm` with volumes