Fixing the version number of ANTLR runtime library.

Antlr 3.1 can be downloaded from Python Package Index 

See #6:
http://github.com/meisam/YSmart/issues/issue/6
Updating setup.py to use disutil (or pip) for installing YSmart.

YSmart is packaged into 3 parts now:
* ysmart.frontend which is in SQL2XML directory now
* ysmart.backend which is in XML2MapREduce
* ysmart.test which is in test

*I need to change the directory structure and put all the source code in
one directory, all scripts in one directory, and all test in one
directory.

See #6:
http://github.com/meisam/YSmart/issues/issue/6
Adding the missing __init__.py files to the packages

See #6: Use distutils and remove sys.path.append(XXX) lines from the
code 
http://github.com/meisam/YSmart/issues/issue/6
Removing the Antlr3 runtime files from YSmart.

Antlr3 should be installed with distutils (or pip).

See #6: http://github.com/meisam/YSmart/issues/issue/6
Reorganizing the directory structure in YSMart based on the package
names

All source files are in the src folder now
All test cases are in tests folder now

See #6: http://github.com/meisam/YSmart/issues/issue/6