Merge pull request #5 from wasabiz/master

varaible initializer support
Merge pull request #6 from wasabiz/master

don't require 'return 0' at the end of main function
Merge pull request #7 from wasabiz/master

results of (!), relative operators and equality operators must be either
Merge pull request #8 from wasabiz/master

support single statement block
support switch statement