Add classes encapsulatinglegacy USB API

Added implementation for endpoints and overlapped I/O support for legacy API support.
diff --git a/host/windows/usb/api/SOURCES b/host/windows/usb/api/SOURCES
index 4b9d360..f6e6614 100755
--- a/host/windows/usb/api/SOURCES
+++ b/host/windows/usb/api/SOURCES
@@ -88,6 +88,7 @@
 SOURCES = adb_api.cpp                     \

           adb_endpoint_object.cpp         \

           adb_winusb_endpoint_object.cpp  \

+          adb_legacy_endpoint_object.cpp  \

           adb_helper_routines.cpp         \

           adb_interface.cpp               \

           adb_winusb_interface.cpp        \

@@ -95,6 +96,7 @@
           adb_interface_enum.cpp          \

           adb_io_completion.cpp           \

           adb_winusb_io_completion.cpp    \

+          adb_legacy_io_completion.cpp    \

           adb_object_handle.cpp           \

           AdbWinApi.cpp                   \

 		      AdbWinApi.rc