rename some of the classes

CParser is now just parser. CTree is now Schema. The namespace "schema" is
now called "yang".

Change-Id: Ief9c22fb6a7633b80010d355f9582e313e818d45
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2c9975e..7513c87 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -55,8 +55,8 @@
 add_definitions(-DBOOST_SPIRIT_X3_NO_FILESYSTEM)
 
 set(parser_SRCS
-    src/CTree.cpp
-    src/CParser.cpp
+    src/schema.cpp
+    src/parser.cpp
     src/ast.cpp
     src/utils.cpp
     src/parser_context.cpp