Rename GetAstType method to GetParseTreeType.
Rename IAstEmitter to IParseTreeEmitter.
Rename RuleAstEmitter to RuleParseTreeEmitter.
Rename SimpleRuleAstEmitter to SimpleRuleParseTreeEmitter.
Rename ExtensibleRuleAstEmitter to ExtensibleRuleParseTreeEmitter.
Rename ExtensionRuleAstEmitter to ExtensionRuleParseTreeEmitter.
Rename ExtendSyntaxAstEmitter to ExtendSyntaxParseTreeEmitter.
Rename SplicableAstWalkerEmitter to SplicableParseTreeWalkerEmitter.
Rename Ast directory to ParseTree.
Rename variables.
Rename methods.
Change splicable parse tree suffix to "ParseTreeWalker".
Change variable name in generated code.