ps3ntfs_file_to_sectors added to ps3_io.c/ntfs.h
ntfs_file_to_sectors added to ntfsfile.o/ntfsfile.h
ntfs_file_to_sectors added to ntfs.c
file_to_sectors added to devoptab_t (iosupport.h)

ntfsMountAll (ntfs.c) would mount ext volumes with "ntfs" path, unlike ntfsMountDevice.
The part of code that sets mount name was copy pasted from ntfsMountDevice into ntfsMountAll to correct this.

The added functions are based on ntfs_open_r, ntfs_read_r, and ntfs_attr_pread_i source codes.
A bit ugly, for cleaning, the repeated 512 constant should be replaced with proper code, and the comments from the copy pasted code removed. 
