add support for obtaining sense status and source slot of a media

add support for obtaining sense status and source slot of a media

this fixes a bug in bacula where the catalog was not properly kept
up-to-date if a tape was in a drive becuse its source slot was
unknown

based on code from FreeBSD; ok krw@

picker 0:  sense: <0x00/0x00> voltag: <:0> avoltag: <:0> source: <>
slot 0: <ACCESS,FULL> sense: <0x00/0x00> voltag: <XX1168L1:0> avoltag: <:0> source: <slot 0>
slot 1: <ACCESS,FULL> sense: <0x00/0x00> voltag: <XX1187L1:0> avoltag: <:0> source: <slot 1>
slot 2: <ACCESS,FULL> sense: <0x00/0x00> voltag: <XX1184L1:0> avoltag: <:0> source: <slot 2>
slot 3: <ACCESS,FULL> sense: <0x00/0x00> voltag: <XX1195L1:0> avoltag: <:0> source: <slot 3>
slot 4: <ACCESS,FULL> sense: <0x00/0x00> voltag: <XX1037L1:0> avoltag: <:0> source: <slot 4>
slot 5: <ACCESS,FULL> sense: <0x00/0x00> voltag: <XX1038L1:0> avoltag: <:0> source: <slot 5>
slot 6: <ACCESS,FULL> sense: <0x00/0x00> voltag: <XX1166L1:0> avoltag: <:0> source: <slot 6>
slot 7: <ACCESS,FULL> sense: <0x00/0x00> voltag: <XX1167L1:0> avoltag: <:0> source: <slot 7>
slot 8: <ACCESS,FULL> sense: <0x00/0x00> voltag: <XX1180L1:0> avoltag: <:0> source: <slot 8>
slot 9: <ACCESS,FULL> sense: <0x00/0x00> voltag: <XX1186L1:0> avoltag: <:0> source: <slot 9>
slot 10: <ACCESS> sense: <0x00/0x00> voltag: <:0> avoltag: <:0> source: <picker 0>
slot 11: <ACCESS,FULL> sense: <0x00/0x00> voltag: <XX1182L1:0> avoltag: <:0> source: <slot 11>
slot 12: <ACCESS,FULL> sense: <0x00/0x00> voltag: <XX1181L1:0> avoltag: <:0> source: <slot 12>
slot 13: <ACCESS,FULL> sense: <0x00/0x00> voltag: <XX1196L1:0> avoltag: <:0> source: <slot 13>
slot 14: <ACCESS,FULL> sense: <0x00/0x00> voltag: <XX1169L1:0> avoltag: <:0> source: <slot 14>
slot 15: <ACCESS,FULL> sense: <0x00/0x00> voltag: <XX1197L1:0> avoltag: <:0> source: <slot 15>
slot 16: <ACCESS,FULL> sense: <0x00/0x00> voltag: <XX1165L1:0> avoltag: <:0> source: <slot 16>
slot 17: <ACCESS,FULL> sense: <0x00/0x00> voltag: <XX1199L1:0> avoltag: <:0> source: <slot 17>
slot 18: <ACCESS,FULL> sense: <0x00/0x00> voltag: <XX1189L1:0> avoltag: <:0> source: <slot 18>
slot 19: <ACCESS,FULL> sense: <0x00/0x00> voltag: <XX1185L1:0> avoltag: <:0> source: <slot 19>
slot 20: <ACCESS,FULL> sense: <0x00/0x00> voltag: <XX1198L1:0> avoltag: <:0> source: <slot 20>
slot 21: <ACCESS,FULL> sense: <0x00/0x00> voltag: <XX1039L1:0> avoltag: <:0> source: <slot 21>
slot 22: <ACCESS,FULL> sense: <0x00/0x00> voltag: <XX1035L1:0> avoltag: <:0> source: <slot 22>
slot 23: <ACCESS,FULL> sense: <0x00/0x00> voltag: <XX1188L1:0> avoltag: <:0> source: <slot 23>
drive 0: <ACCESS,FULL> sense: <0x00/0x00> voltag: <XX1183L1:0> avoltag: <:0> source: <slot 10>