Dynamic index directory name - deleting lock files

[vzak-profimedia]

Hi, solr cloud in some situations during replication renaming index directory to name with timestamp.

in this situation there is a index.properties file in a data directory. index.properties file contains data like that:

#index.properties #Thu Apr 19 07:57:32 UTC 2018 index=index.20180419074545695

Dynamic index directory name could be created during replication.

It would be great if solr startup script, check index.properties file and if exists, then delete lock file in a dynamic index directory.

[vzak-profimedia]

#35