This function provides a shortcut to reformatting a mounted filesystem.
Also, since this function is a virtual member of the FileSystem class,
the user does not need to know the underlying filesystem to reformat
the underlying storage.
The old open/opendir functions did not provide a route for errors and
relied on implementations manually setting errno. Updated to return
errors directly.
Required for other representations of FileSystems, ie LocalFileSystem
Introduces FileSystemHandle for the same behaviour as FileHandle and
DirHandle.
Requires the following to hook into file/dir lookup:
```
int open(FileHandle **file, const char *filename, int flags)
int open(DirHandle **dir, const char *path)
```
This hook is provided by the FileSystem class, so requires no changes
from implementations.
Intention is to make filesystem api and network stack api consistent
as current designs diverge greatly. Attempted to change as little as
possible outside of api structure.
Christopher Haster
Kevin Bracey