Added Markup module.

- All classes and incomplete unit tests.
Added: Peach_Markup_None
Merge branch 'develop' into spike
Added Markup module.

- All classes and incomplete unit tests.
Added: Peach_Markup_None
Merge branch 'spike' of https://github.com/trashtoy/PEACH into spike
Implemented tests for Container classes.

- Added Peach_Markup_ContainerTestImpl
- Implemented tests using ContainerTestImpl
Modified Peach_Markup_NodeList

- Fixed comments
- Removed appendNode (Integrated with 'append')
Modified comments for Peach_Markup_Container.
Added Peach_Markup_NoneTest
Removed CDATA section support

Others:

- Modified comments
- Implemented tests for Renderer classes
Removed appendNode() from Peach_Markup_Comment

- Integrated with append()
Added getOriginal() for BreakControlWrapper
Implemented tests for Peach_Markup_Text
Fixed Exception type

- Exception => InvalidArgumentException
Implemented tests for Peach_Markup_EmptyElement

- Applied implementation of Peach_Markup_ElementTest
Modified setter methods of DefaultBuilder

- TODO: tests incompleted.
Implemented tests for Peach_Markup_Code
Added echoMode support
Implemented tests for Context classes

Others:

- Removed CDATA section support