This should make it work on OSX.
Also, split unmount into two functions. Depending on what you
want,
* UnmountErr returns the resulting error
* UnmountPanic panics if the error was not nil
...and add tests for checking that gocryptfs.diriv
does not get created.
The main "integration_tests" package has become quite
big and convoluted over time.
This small separate package should make writing tests
for "-plaintextnames" easier.
As seen in "fusefrontend: fix PlaintextNames versions of Mkdir, Rmdir",
we need more of them.