configurable solr-webapp directory [JIRA: RIAK-1689]

[michellep-basho]

customer request:
Ability to configure /var/lib/riak/solr-webapp directory via
riak.conf, like bitcask root directory. Kota can provide additional details.

[joedevivo]

This actually belongs here in the yokozuna project. The change is made in priv/yokozuna.schema

[rzezeski]

See basho/node_package#138, #387 and #397. Do we really need to make this configurable? Please cite the reasons.

[kuenishi]

This is not a strong demand but a mild request to ease customer's configuration management. I'm asking more about what they specifically do want to change on solr-webapp.

[lukebakken]

Without this change, data will be written to a directory that a customer may not want anything written. Specifically, if Riak is installed to a read-only filesystem, while the data directories point elsewhere.

[DSomogyi]

Comment for Jira.

[joedevivo]

Comment for JIRA