client: Queue events while the IBus context isn't ready

There are actually 3 patches here.

---
client: Queue events while the IBus context isn't ready

We may lose events that ought to be processed while the IBus context
isn't ready or if the connection to IBus isn't fully established yet.

To avoid that, enqueue events to be processed later when the IBus
context creation finishes.

---
client: Don't cancel an ongoing create input context on another request

This would only add more delays.

---
client: Cancel any ongoing create input context request on finalize

BUG=

Review URL: https://codereview.appspot.com/6988047
Patch from Rui Matos <tiagomatos@gmail.com>.
Fix no rule to make target test-override-ibus.py

BUG=http://code.google.com/p/ibus/issues/detail?id=1592

Review URL: https://codereview.appspot.com/7332043
Show all GIR warnings
Fix annotation in ibus_bus_create_input_context

BUG=http://code.google.com/p/ibus/issues/detail?id=1593

Review URL: https://codereview.appspot.com/7368044
daemon: allow "eavesdrop" match rule

Recent dbus-monitor supplies "eavesdrop" match rule which ibus-daemon
does not accept.  This patch silently ignores the rule so ibus-daemon
behave the same as before.

BUG=none

Review URL: https://codereview.appspot.com/7225062
Fix make rpm errors due to ibus-dconf and pygobject override

BUG=Issue#1600

Review URL: https://codereview.appspot.com/7404047
Implement use-system-keyboard-layout

BUG=http://code.google.com/p/ibus/issues/detail?id=1558

Review URL: https://codereview.appspot.com/7414045
Change set_use_system_keyboard_layout() timing.

Call set_use_system_keyboard_layout() before update_engines() is called
in panel.vala because update_engines() calls switch_engine().

BUG=http://code.google.com/p/ibus/issues/detail?id=1558#c43

Review URL: https://codereview.appspot.com/7559043
Launch the second ibus engine too to reduce the launching time.

Currently the first ibus engine only is running but the second engine
is also frequently used. It is good to run the second engine before
user types Ctrl+space.

BUG=RH#838734
TEST=src/tests/ibus-bus

Review URL: https://codereview.appspot.com/7433049
Simplify component xml generation using sed

BUG=none

Review URL: https://codereview.appspot.com/7445048
Add textdomain property to IBusEngineDesc

BUG=Issue#1580

Review URL: https://codereview.appspot.com/7692043
bash completion: No need to install it as executable.

BUG=http://code.google.com/p/ibus/issues/detail?id=1601

Review URL: https://codereview.appspot.com/7696043
Patch from Ville Skyttä <ville.skytta@iki.fi>.
Move ibus.bash script from /etc to /usr/share

BUG=RH#922996

Review URL: https://codereview.appspot.com/7863045
Merge pull request #6 from maxiaojun/master

Show all g-ir-scanner warnings
Fix build error and warnings in Fedora 18.

BUG=None
TEST=Manual

Review URL: https://codereview.appspot.com/7531047
Draw highlight for focused IME in IME switcher.

BUG=None
TEST=Manual

Review URL: https://codereview.appspot.com/7689046
Release 1.5.2

Review URL: https://codereview.appspot.com/7530044