mboxd: Update mboxd to implement protocol V2 and add dbus support

Version 2 of the mbox protocol contains a few changes such as:
 - All sizes are in block size
 - Adds an erase command
 - Adds new response codes
 - Adds new BMC events
 - Open windows commands now take a size directive

Update the mailbox daemon to support version 2 of the protocol which
includes implementing all of the V2 functionality. Also entirely refactor
the mboxd.c code to make it more modular improving readability and
maintainability.

At the same time improve the functionality by adding:
 - Multiple windows in the daemon (still only one active window) to cache
   flash contents
 - Implement a dbus interface to allow interaction with the daemon
 - Handle sigterm and sigint and terminate cleanly

The previous implementation utilised the entire reserved memory region.
Update the daemon so that on the command line the number of windows and
the size of each which the reserved memory region will be split into can
be specified. The reserved memory region is then divided between the
windows, however there can still only be one "active" window at a time.
The daemon uses these windows to cache the flash contents meaning the
flash doesn't have to be copied when the host requests access assuming
the daemon already has a copy.

A dbus interface is added so that commands can be sent to the daemon to
control it's operation from the bmc. These include suspending and resuming
the daemon to synchronise flash access, telling the daemon to point the lpc
mapping back to flash and telling the daemon when the flash has been
modified out from under it.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Change-Id: I10be01a395c2bec437cf2c825fdd144580b60dbc
diff --git a/Makefile.am b/Makefile.am
index 2b86e66..0947425 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,6 +1,6 @@
 ACLOCAL_AMFLAGS = -I m4
 sbin_PROGRAMS = mboxd
 
-mboxd_SOURCES = mboxd.c common.c
-mboxd_LDFLAGS = $(SYSTEMD_LIBS)
-mboxd_CFLAGS = $(SYSTEMD_CFLAGS)
+mboxd_SOURCES = mboxd.c common.c mboxd_dbus.c mboxd_flash.c mboxd_lpc.c mboxd_msg.c mboxd_windows.c
+mboxd_LDFLAGS = $(LIBSYSTEMD_LIBS)
+mboxd_CFLAGS = $(LIBSYSTEMD_CFLAGS)