Application startup improvements.

Can now run GUI in two ways:

1. Via scons from software/openvisulizer directory, which uses
openVisualizerApp/openVisualizerGui.py,

2. Via traditional command line in software/openvisualizer/bin/openVisualizer
directory.

.gitignore -- Ignore build directory and scons work files.

SConstruct -- Set a default directory for firmware directory parameter.
Start to use openVisualizerGui implementaion in openVisualizerApp dir.

openVisualizerApp/openVisualizerGui.py -- Remove sys.path initialization.
Rework logging initialization.

openVisualizerGui/openVisualizerGui.py -- Revert to latest version from
develop branch. Also set path for openwsnmodule_obj.h in moteHandler, as
described below.

openVisualizerApp.py -- Add options for working directory and firmware
directory. Set path for openwsnmodule_obj.h in moteHandler, as described
below. Replace deprecated optparse with argparse for parsing options.

moteHandler -- Don't determine location for openwsnmodule_obj.h. Instead,
require calling app to provide this path in a call to new function
readNotifIds().