apply async check only when it is allowed
fix failing unit tests
add more unit tests & update javadoc
resourceWatcher should not check for changes when tryAsyncCheck is invoked and request is not handled by WroFilter, to play nicely with wro taglibs which invokes wro api server-side
Merge branch 'issue822' into 1.7.x
Merge remote-tracking branch 'origin/1.7.x' into 1.7.x