Fix to make a file read binary if such mode was set.
Fix to make a file read binary if such mode was set.

bquorning/fakefs,dekz/fakefs,1234-/fakefs,fakefs/fakefs,anthonyryan1/fakefs,defunkt/fakefs,onehub/fakefs,vhl/fakefs,deployable/fakefs,marxarelli/fakefs,pivotal-cf-experimental/fakefs