Add log4cpp files to Externals
CMake changes for Windows (quite minor)
Example usage in diagram app
Trying another layout
Trying a file appender
Hook up some real scirun code with log4cpp
Test log4cpp with multithreaded code: success!
Comment out install commands
Merge branch 'tetVol' into log4cpp
OSX version of config.h
Remove logging example. Doesn't crash now!

???
Merge branch 'log4cpp' into misc_F2

Conflicts:
	src/CMakeLists.txt
Closes #294.
Closes #350