Added Request Logging and example to demo spark.gsp
Request Logging mixin functionality to give user more control of what to log and when
Very basic trace stack
Merge branch 'master' of git://github.com/jchoigw/sparkgs

Conflicts:
	demo/spark.gsp
	src/main/java/sparkgs/SparkGSFile.gs
Logging supports lazy message construction now.

Log some basic request info as well