Refactored command, front, and agent system. And fixed many bugs.
Unified lib/pione/model and lib/pione/lang.
Refactored use of name space about Pione::Util.
Refactored use of name space about Pione::System.
Update test.
Unified Pione::Parser and Pione::Transformer into Pione::Lang.
Update test.
Fixed bugs in tests.
Removed unneeded files.
Unified Pione::URIScheme and Pione::Location.