Prototyping...
Implement and test CharScanner for <script> element
Add a trie for symbols
Test on web browser
Fix to run and find some lost code
Add Gruntfile.js and grunt watch-and-browserify
Remove temporary alert() for debugging
Implement LLParser
Eliminate Left Recursion in Rvalue, Mag, Term
add new token assign, implement takeExpr method
Extends Expr type hierarchy in LLParser and AST
Implement unimplemented ASTs in LLParser
Extend syntax specification of MiniC (more similar to C)

- function call
- declaration first
Prepend to implement the semantic analyzer
Implement ScopeStack and ASTVisitor of SymanticAnalysis (WIP)
Test scoping rules and prepare type checking
expr type inferring finished. TODO: ReturnStmt type checking
change getType to inferType
add error case to Mag.inferType
Complete to check type rules (e.g. function), ensure Type.* is singleton