BibIndex: virtual global index
BibIndex: virtual global index

* Turns global index into a virtual index and
   hanges indexing engine to index virtual indexes
  during indexing physical indexes.  (closes #1574)

* Creates new idxINDEX_idxINDEX table which stores
  information about virtual indexes and their
  dependencies.

* Modifies functions for searching for affected
  indexes to be aware of virtual indexes.

* Adds miscellaneous index and field.

* Adds new tags for miscellaneous index.

* Enhances bibindex administration interface
  accordingly.

Signed-off-by: Grzegorz Szpura <900c4f131187ed2a7cfcf1f0200fa0b9c64b7780@cern.ch>
Tested-by: Tibor Simko <c7116e45300b163846dc01f3ed02116e3f8ef7a5@cern.ch>

tiborsimko/invenio-formatter,tiborsimko/invenio-formatter,inveniosoftware/invenio-formatter,inveniosoftware/invenio-formatter,tiborsimko/invenio-formatter,inveniosoftware/invenio-formatter