Changed the nud that relate to parseStatement().
Modify the parseStatement and parseStatements so that both returning a list of objects
parseStatement() an declaration statement will return a list.
Extended the parsing on the declarationContext.
Completed the function to generate 'sub' and 'ldr' byteCode.
Fixed the byteCode for variable initialization.
Merge https://github.com/bingxuan3133/CInterpreter
Merge pull request #14 from jwchong93/master

Merged with Bing Xuan code