Code simplification in AttributeIndex

Code review: Matthew Swift


AttributeIndex.java:
Removed getEqualityIndex(), getApproximateIndex(), getOrderingIndex(), getSubstringIndex(), getPresenceIndex() and getIndexById() methods, all replaced with the new getNameToIndexes() and getDefaultNameToIndexes() methods.

Importer.java, IndexQueryFactoryImpl.java, Suffix.java, VerifyJob.java:
Consequence of the change to AttributeIndex + added toImportIndexType(String IndexID)