closes #4 Refactor DBC parsing into TypeFactory statement handlers

dbc.pro

@@ -7,6 +7,7 @@ SOURCES += \
         dbc_decode_builder.cpp \
         dbc_decoder.cpp \
         dbc_parser.cpp \
+        dbc_statement_handler.cpp \
         dbc_tree_builder.cpp \
         main.cpp \
         tree_node.cpp
@@ -16,6 +17,8 @@ HEADERS += \
   dbc_decode_builder.h \
   dbc_decoder.h \
   dbc_parser.h \
+  dbc_statement_handler.h \
+  typefactory.h \
   dbc_tree_builder.h \
   decode_database.h \
   frame_info.h \