untaint config data for epindexer

Uses perl regexp capture groups to untaint config data before using it
to execute the indexer. Also provides some actual sanitisation.

Fixes an issue introduced at 8fefac3
use $prefix for base_path
Merge pull request #279 from QUTlib/feature/untaint_config

untaint config data for epindexer
Added missing phrase document_typename_application/adobe
commited code by TMB for addition of Subject sort name field. Need to update database to add the new field to Subject DataObj.  Fixed an issue where the subject order value is not respected in browse view menu (e.g browse by division)