Rewrite SQL++ functions.

-Maps SQL function names to internal names.
-Allows SQL++ builtin functions to be case-insensitive.
-Rewrites SQL-92 global aggregates.
-Refactors SQL++ AST visitors.
-Cleans up semantics of COLL_AGG and SQL-92 AGG.

Change-Id: Idb5a7c6780669b27065b0928bec7e4700cfb53a9
Reviewed-on: https://asterix-gerrit.ics.uci.edu/759
Tested-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Reviewed-by: Till Westmann <tillw@apache.org>
diff --git a/asterix-app/src/test/resources/optimizerts/queries_sqlpp/query-issue697.sqlpp b/asterix-app/src/test/resources/optimizerts/queries_sqlpp/query-issue697.sqlpp
index 5d23126..813109a 100644
--- a/asterix-app/src/test/resources/optimizerts/queries_sqlpp/query-issue697.sqlpp
+++ b/asterix-app/src/test/resources/optimizerts/queries_sqlpp/query-issue697.sqlpp
@@ -37,7 +37,7 @@
 
 create  table test(TestType) primary key key1;
 
-select element {'gid':aid,'avg':test.avg((
+select element {'gid':aid,'avg':test.coll_avg((
         select element j."value"
         from  i as j
         where test.not(test."is-null"(j."value"))