UIMA enhancements to allow for dynamic AE detection

I've been sitting on this patch for over 2 years (and likewise it's been running IN production for the same) ... finally got around to contributing it back to the community.  This change prepares the UIMAUpdateRequestProcessor to allow subclasses to have additional control over how the analysis engine is selected.  In my case, I wrote a sub-class that allows for dynamic detection of the UIMA analysis engine based on the document fields.  ie: a field in the document can be used to select different UIMA configurations and rules.

Can someone please commit this as soon as possible.  I don't necessarily need it to be back-ported, having in 7.4.1 would suffice.

Thanks!