Cookie should include index directory

[ivankelly]

JIRA: https://issues.apache.org/jira/browse/BOOKKEEPER-824

Reporter: Charles X

after introduced index directory, the cookie isn't upgraded to include the index directories, which potentially break data integrity

Comments from JIRA

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Sijie Guo 2016-03-14T05:52:49.500+0000

[~agarg1986] are you able to produce a patch before end of the month?

[ivankelly]

@sijie we currently add the index directories to the ledger dirs part of the cookie. This isn't 100% safe though, as if someone swapped around their index directories and ledger directories in the conf, they would lose data.

Bumping to release/4.8.0 in any case.

[sijie]

@ivankelly agreed.