SolrUtils: support entire full-text indexing
SolrUtils: support entire full-text indexing

* Indexes entire possibly long documents.

Signed-off-by: Patrick Glauner <5443b88bc6611431eef05c8ef00b7fee188ca13d@cern.ch>
Tested-by: Tibor Simko <c7116e45300b163846dc01f3ed02116e3f8ef7a5@cern.ch>

tiborsimko/invenio,inveniosoftware/invenio,inveniosoftware/invenio,tiborsimko/invenio