Add new "qemu monitor" command to the console.

This allows you to access the QEMU virtual machine monitor directly
from the console (instead of playing with the command-line to do it).

The implementation of the 'quit' command has been modified to simply
close the connection, instead of stopping the emulator program.

This patch introduces changes that allow a console session to be
detached and redirected at runtime to other internal services of
the emulator program. This will be useful in the future to implement
other features.

+ doc typo
+ add proper definitions for CONFIG_ANDROID on config-host.h
+ remove obsolete sysdeps.h dependency in android/console.c

Change-Id: If16cfe41c12a26eb8f56e3a9c24452eafa5efab4
diff --git a/telephony/android_modem.c b/telephony/android_modem.c
index 1e060dd..2f4c98e 100644
--- a/telephony/android_modem.c
+++ b/telephony/android_modem.c
@@ -359,6 +359,8 @@
 
     modem->sim = asimcard_create(base_port);
 
+    sys_main_init();
+
     return  modem;
 }