Tvshow multipaths parentid

This replaces #4843 with storing the parentid in the path table.

Later on we can use this for GetScraperByPath() etc, but I'd prefer to get it in and work on that during the next month.

@Montellese any particular opposition to merging as-is?
The above SQL is throwing error 1093 during the db upgrade.

According to MySQL Workbench, error 1093 is:
```
Error Code: 1093. You can't specify target table 'seasons' for update in FROM clause
```
Log extract:
````
05:45:06  19.740480 T:3059241504   ERROR: Unable to open database: MyVideos85 [1049](Unknown database 'MyVideos85')
05:45:06  19.746349 T:3059241504   ERROR: Unable to open database: MyVideos84 [1049](Unknown database 'MyVideos84')
05:45:06  19.752527 T:3059241504   ERROR: Unable to open database: MyVideos83 [1049](Unknown database 'MyVideos83')
05:45:06  19.759798 T:3059241504   ERROR: Unable to open database: MyVideos82 [1049](Unknown database 'MyVideos82')
05:45:06  19.765892 T:3059241504   ERROR: Unable to open database: MyVideos81 [1049](Unknown database 'MyVideos81')
05:45:06  19.772024 T:3059241504   ERROR: Unable to open database: MyVideos80 [1049](Unknown database 'MyVideos80')
05:45:06  19.783268 T:3059241504  NOTICE: Old database found - updating from version 79 to 85
05:45:17  30.576199 T:3059241504  NOTICE: Attempting to update the database MyVideos85 from version 79 to 85
05:45:27  40.041969 T:3059241504   ERROR: SQL: Undefined MySQL error: Code (1093)
                                            Query: DELETE FROM seasons WHERE idSeason NOT IN (SELECT min(idSeason) FROM seasons GROUP BY idShow,season)
05:45:27  40.049629 T:3059241504   ERROR: Exception updating database MyVideos85 from version 79 to 85
05:45:27  40.049843 T:3059241504   ERROR: Error updating database MyVideos85 from version 79 to 85
05:45:27  40.075493 T:3059241504  NOTICE: Old database found - updating from version 78 to 85
05:45:27  40.080177 T:3059241504   ERROR: SQL: Can't create database for copy: 'MyVideos78' (1007)
05:45:27  40.080475 T:3059241504   ERROR: Unable to copy old database MyVideos78 to new version MyVideos85
```