build: consolidate to use one convenience lib

The original motivation for for splitting libbuxton-security out of
libbuxton-shared was to avoid using the duplicate Smack rule hashmap
from libbuxton back when bt-daemon linked with libbuxton.

Now that bt-daemon no longer links with libbuxton, and more functions
moved into shared/backend.c that should contain access checks, the
original reason for the split is no longer valid, making
libbuxton-security unnecessary.

This commit re-integrates the security lib in the common -shared
convenience library.
smack: fix read_access API

Use BuxtonControl instead of a BuxtonClient for the first arg, aligning
with the write_access API.

This problem went unnoticed because read_access does not currently use
the BuxtonControl arg for anything, but that may change in the future.
backend: pass client Smack labels through internal API

To accomodate correct access checks for get_value priority logic, the
internal backend API needs access to the client Smack label.

For consistency, do the same thing for the set_value and unset_value
functions.

The access checks will be migrated in a future commit.
smack: move access checks to their proper locations

Now that the backend API has access to the client Smack labels, we can
do the Smack access checks here instead.
shared: Add BuxtonControlMessage to notify_value

In buxton_wire_handle_response, with BuxtonControlMessage, the client
library handles notification registration seperately from other daemon
responses (still need to add handling for unnotify response). It will
check the response's status and if registration was successful, add
the notify_value to the notify_callbacks hashmap.
API: Add unsigned integer data types

Signed-off-by: William Douglas <william.douglas@intel.com>
core: Correct log message

Signed-off-by: William Douglas <william.douglas@intel.com>
core: unregister_notification returns notification msgid

When the daemon removes a client from notification list, the daemon
will send the message id for the notification to the client in its
response (to be used by the client to remove the callback from the
notification hashmap, not yet implemented).
shared: Remove message ID from notification callbacks

On unregister_notification, remove the message ID the daemon returns
from the notify_callbacks hashmap.

Signed-off-by: William Douglas <william.douglas@intel.com>
Eliminate some problems flagged by static analysis

Signed-off-by: Michael Leibowitz <michael.leibowitz@intel.com>