Add AugmentationCollection::loadFromDirectory().

Takes the functionality from TraceViewerApp.cpp, in preparation
for the console applications supporting augmentations.
Use common wxConfig between applications.

seec-print and seec-view now use a common data directory for user
information, including configuration. This will allow the user to select
settings in the trace viewer, and have them honoured in the other
applications (and soon in the runtime library).

This commit also enables augmentation for runtime error messages in
seec-print, loading augmentations from the resource directory.
Support augmentations in the runtime library.

This enables augmentations in the runtime error descriptions printed by
the runtime library during execution (i.e. when the error is detected).
Load augmentations from the user's data directory.

Augmentations are loaded from the folder "augment" in the user's local
data directory.

Previously setupCommonConfig() used a temporary wxAppConsole (if there
wasn't already a running wxApp) which was destructed at the end of the
function. It's now necessary for clients to setup a wxApp instance. The
function "setupDummyAppConsole()" is now public to facilitate this for
clients that don't care about the particular instance (e.g. seec-print
and the runtime library), and now automatically registers the
appropriate shutdown function using std::atexit().