notify: dynamically allocate filename buffer

use asprintf to dynamically allocate filename buffer
rather than just reserving 512 bytes on the stack to
avoid potential overflow.

Change-Id: Ieeb9c6c2e5f97a9574f8128d84eba0b8efdb7263
Disable vendor id filtering for OS X.

Companion patch for change I2bf583a27f9a3f98ef006ea62b906a4f89960507.

Due to the use of USB class 0xff it's not possible to register a listener
which uses the OS methods for filtering notifications, so this patch
also introduces a check in the notification listener which checks the
class, subclass, and protocol for the interface each notification relates 
to.

Change-Id: I380cc80f96addc5057660efb2179b35f9378886a
Remove explict use of ASCII encoding

Replace the use of CFStringGetCString with kCFStringEncodingASCII specified
with CFStringGetFileSystemRepresentation which will ensure the correct
character encoding is used to conver the CFString into a NULL terminated
char array suitable for use with POSIX APIs.

Change-Id: Ibab1dc05c4f4db8604d329a493b4241992b8e69d
Merge "Remove explict use of ASCII encoding"
Merge "Disable vendor id filtering for OS X."
Remove the adb usb vendor id whitelist.

If there are bad vendors, we should blacklist them. Whitelisting the entire
world is crazy.

Change-Id: I1f4c27fd34fc420e2a3b4b2c8749198030db69f1
Merge "Remove the adb usb vendor id whitelist."
Merge "notify: dynamically allocate filename buffer"