Fix a few errors concerning use of section block comments in .c files: (#95)

1. No .c file should include a "Public Types" section.  Only a header file can define a public type.  A .c file can only define a private type.  Several files contained private type definitions.  The section that they were defined in, however, was incorrectly named "Public Types."  Those were easilty changed to "Private Types" which is what they are.

2. No .c file should include a "Public Function Prototypes" section.  All global function prototypes should be provided via a header file and never declared with a .c file.

For No. 2, I corrected as many cases as was reasonable for the time that I had available.  But there are still a dozen or so .c files that declare "Public Function Prototypes" within a .c file.  This is bad programming style.  These declarations should all be moved to the proper header files.

wireless/bluetooth/bt_ioctl.c

@@ -59,7 +59,7 @@
 #ifdef CONFIG_NETDEV_IOCTL  /* Not optional! */
 
 /****************************************************************************
- * Public Types
+ * Private Types
  ****************************************************************************/
 
 /* These structures encapsulate all globals used by the IOCTL logic. */