CB-5404: Fix fragile file tests

Several tests are dependent on whether directory paths end in '/' or
not. Also, manually-created file and directory entries should have an
associated filesystem attribute. This patch fixes both issues.
CB-5404: Add test for actually reading directory contents
CB-5405: Update tests to work with URL paths in File objects
CB-5405: Remove test that doesn't make sense for filesystem URLs
CB-5403: Remove test for undocumented File API quirks
CB-5466: Use URLs rather than full paths in file transfer tests
CB-5404: Fix three tests that were sensitive to existing files
added amazon-fireos to platforms
CB-5404: Change filename shared between two file tests
Set VERSION to 3.4.0-dev (via coho)
CB-5214 Make mobile spec tests on WP8 to run w/o user interaction
correct way to detect windows phone (both 7/8)