Fix disambiguated display name on case insensitive file systems

blah/Foo/bar.cpp and blubb/foo/bar.cpp should not be shown as
Foo/bar.cpp and foo/bar.cpp

Change-Id: I900606c63996eea4c11d09ff13579b6cc031a8c6
Reviewed-by: Orgad Shaneh <orgads@gmail.com>