[DAEMONS] mterm: Minor fixes

Signed-off-by: Anup Patel <anup@brainfault.org>
[CORE] Don't allow same function to be registered twice as recevier to a vserial port

Signed-off-by: Anup Patel <anup@brainfault.org>
[LIBS] netstack: Added socket API interface and implemented it for lwIP

Signed-off-by: Anup Patel <anup@brainfault.org>
[DAEMONS] Added telnet remote managment support

Signed-off-by: Anup Patel <anup@brainfault.org>
Merge remote-tracking branch 'upstream/master' into dev_exynos4