#45 TSK_FS_NAME_i_j and TSK_FS_META_i_j

Currently SleuthKit defines constants for TSK_FS_NAME_stuff_ENUM and a TSK_FS_META_stuff_ENUM. The constants are used to indicate different file types, and "stuff" includes FIFO, CHR, DIR, BLK, REG , SOCK, SHAD WHT, VIRT, and UNDEF

Since the constants have the same names (but different values), I think that it would be easier and to simply have one set of constants that are used by both the NAME layer and the META layer.

This would result in code simplification.