Installing the pred eval query spiff.
Added most of the code handling this particular query spiff's creation and loading. Will need to add instantiation code.
Updated configure
the creation of this query spiff works now. Will add instantiation code. Note that srminterface.h should belong to SRM instead of postgres. Will decide on how to elegantly include this header.
Added the first query spiff that performs predicate evaluation.

There are a few more changes needed in the spiff-creation code and instantiation. Specifically, multiple versions of the spiff (proto) need be handled and
the IDs of these versions should be properly redesigned in concert with SRM.
Adding the capability of creating multiple versions of the predicate eval spiff.
Added a missing file that contains the query-spiff related typedefs.
Refined multi-versioning of the predeval query spiff code.
Designing query spiff id.
Linking agaist udis86 as a shared lib. The first query spiff seems working now.
Added the necessary statements to support the dynamic invocation related resource management of query spiffs. By this commit, the predicate eval spiff is functional, with decent speedup observed on query 6.
Merge pull request #1 from datawareventures/rel9_3_stable_spiff_pred_eval

I only ran query 6 and a few other very very simple queries as tests. There are issues that I ignore for now, such as the definitions of the instantiation-related data and the design of passing such arguments. Also, there are hardcoded paths in naming object files... I will work on them in subsequent PRs.

@jgus, please take a look at ```query_spiff_predicate_evaluate.c```. I'm trying to create four distinct versions of the same spiff function. I choose to use pattern-without-data because I need to make sure that the function's signature is consistent with the one it replaces. Let me know if what I had did not make sense.

I'm merging in this PR without regular reviews, as I'm trying to get the first functional query spiff in as soon as I can.