beremiz

fix Traceback if search icon on library panel is clicked, when no
category/item is selected in the library.

The problem is here, that if nothing is selected method GetSelection()
returns root item, that doesn't have any python data associated with it.
This issue seems to be wx3.0 specified, because it doesn't exist
with wx2.8 on Windows.
Beremiz installation
====================
Windows
-------
Download installer, install.
Linux
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Pre-requisites::
# Ubuntu/Debian :
sudo apt-get install python-wxgtk2.8 pyro mercurial
sudo apt-get install build-essential bison flex python-numpy python-nevow
Prepare::
mkdir ~/Beremiz
cd ~/Beremiz
Get Source Code::
cd ~/Beremiz
hg clone http://dev.automforge.net/beremiz
hg clone http://dev.automforge.net/plcopeneditor
hg clone http://dev.automforge.net/matiec
Build MatIEC compiler::
cd ~/Beremiz/matiec
./configure
make
Build CanFestival (optional)::
# Only needed for CANopen support. Please read CanFestival
# manual to choose CAN interface other than 'virtual'::
cd ~/Beremiz
hg clone http://dev.automforge.net/CanFestival-3
cd ~/Beremiz/CanFestival-3
./configure --can=virtual
make
Launch Beremiz::
cd ~/Beremiz/beremiz
python Beremiz.py