1) Fixes Issue 24:Need grammar consistency w.r.t. semicolons
   ';' is the terminator symbol for all AQL statements/queries. As per the last discussion, we decided to keep the terminator symbol optional for create type 
   statement and aql queries. If we choose to make it mandatory for them, I would go ahead an modify all test cases. 
2) Fixed a bug in create dataset syntax that deems the datatype compoenent of a dataset definition as being optionalr, resulting in NPE.
3) Code refactoring centering use of FunctionDescriptors. Code reduction and simplication with interfaces replaced by abstract classes that have default implementation. 


git-svn-id: https://asterixdb.googlecode.com/svn/branches/asterix_stabilization@576 eaa15691-b419-025a-1212-ee371bd00084
20 files changed