Lower the Python requirement

Looking at the Python 3.3 release notes, there shouldn't be anything we
need that isn't in 3.2.3

Many distributions still ship with it, so lowering this requirement is
an easy win towards easier adoption by more distributions.

This is as a commitment on our part to support installation of
ibus-cangje on Python 3.2.3 too. If something works on 3.3 but doesn't
on 3.2.3, we will consider it a bug and fix it.

This goes a long way towards improving the situation described in
bug #16
quick: Handle space after only one input key

In Quick, the candidates are fetched automatically when the user has
inputted 2 keys.

However, if she presses space after only one key, we should implement
the same behaviour as Cangjie: get the candidates, commit it if there is
only one or display them otherwise.
is more than one
Add a summary at the end of configure
Don't force install in IBUS_COMPONENT_DIR

This is just wrong, as it breaks distcheck as well as installing in a
different root (e.g somewhere in $HOME).

Instead we can now use the summary at the end to print a warning if
we're installing in a place where IBus won't find the XML component.
Update the Python required version in the README

Commit 88448e7 lowered the minimum required version of Python to 3.2,
but the README still said 3.3
Mention pygobject in the README
Merge remote-tracking branch 'origin/master'
Trying to fix issue 19