monitor: lib: Support Unix domain socket (UDS) and TCP/IP socket concurrently

monitor: lib: Support Unix domain socket (UDS) and TCP/IP socket concurrently

Previous TCP/IP socket-based IPC has a security issue that
anyone can access the opened port without credential. Since
UDS is exported as a file, we can apply file-based access
control to it. So, we use UDS instead of TCP/IP socket by
default.

At the same time, we also support TCP/IP socket for
resource-monitor-tool which is a web-based monitoring tool
in user space. In the future, we will support TCP/IP socket
only in debugging mode which is turned on/off by root-
privileged command line tool.

Change-Id: Id46a5e7560cf95d09f31222e5022ce3ea209753a
Signed-off-by: Sung-hun Kim <sfoon.kim@samsung.com>