modified 'isQuirks()' method to use a safer 'typeof' check on the '.compatMode' string property since '.indexOf()' will be used on it, slightly changed related comments (jdalton)
modified 'isQuirks()' method to use a safer 'typeof' check on the '.compatMode' string property since '.indexOf()' will be used on it, slightly changed related comments (jdalton)

dperini/nwmatcher,dperini/nwmatcher,dperini/nwmatcher