Fix impropper hid_bus_type declaration

- To match the original declaration in HIDAPI upstream
and avoid compilation errors with newer gcc;
- Include all "system" headers with '<>';
to be explicit that those don't belong to this project/module;

chid.pxd

@@ -1,10 +1,10 @@
 from libc.stddef cimport wchar_t, size_t
 
-cdef extern from "hidapi.h":
+cdef extern from "<hidapi.h>":
     ctypedef struct hid_device:
         pass
 
-    cdef enum hid_bus_type:
+    ctypedef enum hid_bus_type:
         HID_API_BUS_UNKNOWN = 0x00,
         HID_API_BUS_USB = 0x01,
         HID_API_BUS_BLUETOOTH = 0x02,

hid.pyx

@@ -11,10 +11,10 @@ __version__ = "0.14.0"
 hid_init()
 
 
-cdef extern from "ctype.h":
+cdef extern from "<ctype.h>":
     int wcslen(wchar_t*)
 
-cdef extern from "stdlib.h":
+cdef extern from "<stdlib.h>":
     void free(void* ptr)
     void* malloc(size_t size)