removed obsolete css
color coding attempt

- not convinced, but maybe the colors need tweaking, or needs a dark theme
experiments around showing less details by default
more consequent color coding
show/hide stats separately from results, and don't show them by default
fixed issue 291:	PollingConditions doesn't report failed assertion
improved error messages
fixed issue 292:	Provide a Specification.with() overload that states the expected target type

- also added Javadoc for Specification.with()
enhanced and reorganized specs for Specification.with()
Merge branch 'groovy-1.8' into groovy-1.9