Big chunk of changes:

Big chunk of changes:

* Fixed bugs in option parsing
* Simplified the main.cpp significantly (more c++ like)
* Added the null kind, expr value, and expression, with the default constructor public
* Simplified commands, we need to discuss this in the meeting (what to do with command results?)
* Removed all the lex/yacc files
* Symbol table is now a templated class, as we will have tables for variables, predicates and functions
* The ANTLR parsing infrastructure/makefiles is all in. SMT lib Boolean benchmarks should parse + giving nice error such as
      Parse Error: /home/dejan/eclipse-cxx/smtlib-parser/test/test4.smt:3:16: Undeclared variable p
      Parse Error: /home/dejan/eclipse-cxx/smtlib-parser/test/test2.smt:2:11: unexpected token: sa

Didn't add any unit tests as the unit testing doesn't work with the updated build system -- it doesn't know how to create directories in the corresponding build directory.

TODO:
 * add the PL grammar and unit test when the testing becomes available
 * with this build setup my eclipse debugger doesn't work.  Might have something to do with the visibility of symbols?
 * i'm getting g++ depracated warnings regarding the hash_map from the symbol table, need to figure out how to use it in a standard manner. the new <unordered_map> header is for C++0x, and the <ext/hash_map> is getting deprecation warningns... weird.