fix image links in New Protocol Plugins document
fix image links in New Protocol Plugins document

n.b.: These images could very well be replaced by easier maintainable
graphviz graphs.

bryancall/trafficserver,vmamidi/trafficserver,persiaAziz/trafficserver,PSUdaemon/trafficserver,rahmalik/trafficserver,chitianhao/trafficserver,reveller/trafficserver,rpufky/trafficserver,rahmalik/trafficserver,SolidWallOfCode/trafficserver,persiaAziz/trafficserver,chitianhao/trafficserver,taoyunxing/trafficserver,reveller/trafficserver,reveller/trafficserver,PSUdaemon/trafficserver,PSUdaemon/trafficserver,rpufky/trafficserver,duke8253/trafficserver,chitianhao/trafficserver,davidbz/trafficserver,reveller/trafficserver,taoyunxing/trafficserver,reveller/trafficserver,davidbz/trafficserver,chenglongwei/trafficserver,dyrock/trafficserver,dyrock/trafficserver,rahmalik/trafficserver,pbchou/trafficserver,davidbz/trafficserver,clearswift/trafficserver,taoyunxing/trafficserver,PSUdaemon/trafficserver,reveller/trafficserver,SolidWallOfCode/trafficserver,pbchou/trafficserver,vmamidi/trafficserver,chenglongwei/trafficserver,pbchou/trafficserver,chitianhao/trafficserver,duke8253/trafficserver,bryancall/trafficserver,taoyunxing/trafficserver,PSUdaemon/trafficserver,taoyunxing/trafficserver,duke8253/trafficserver,clearswift/trafficserver,chitianhao/trafficserver,taoyunxing/trafficserver,persiaAziz/trafficserver,pbchou/trafficserver,SolidWallOfCode/trafficserver,PSUdaemon/trafficserver,clearswift/trafficserver,PSUdaemon/trafficserver,duke8253/trafficserver,pbchou/trafficserver,rpufky/trafficserver,davidbz/trafficserver,dyrock/trafficserver,chenglongwei/trafficserver,dyrock/trafficserver,taoyunxing/trafficserver,reveller/trafficserver,duke8253/trafficserver,rahmalik/trafficserver,taoyunxing/trafficserver,rpufky/trafficserver,persiaAziz/trafficserver,clearswift/trafficserver,pbchou/trafficserver,vmamidi/trafficserver,PSUdaemon/trafficserver,SolidWallOfCode/trafficserver,rahmalik/trafficserver,rpufky/trafficserver,persiaAziz/trafficserver,bryancall/trafficserver,chenglongwei/trafficserver,dyrock/trafficserver,persiaAziz/trafficserver,chenglongwei/trafficserver,rahmalik/trafficserver,vmamidi/trafficserver,taoyunxing/trafficserver,bryancall/trafficserver,davidbz/trafficserver,duke8253/trafficserver,clearswift/trafficserver,clearswift/trafficserver,chitianhao/trafficserver,vmamidi/trafficserver,rpufky/trafficserver,rahmalik/trafficserver,duke8253/trafficserver,clearswift/trafficserver,reveller/trafficserver,rpufky/trafficserver,rpufky/trafficserver,PSUdaemon/trafficserver,chenglongwei/trafficserver,rpufky/trafficserver,bryancall/trafficserver,vmamidi/trafficserver,bryancall/trafficserver,reveller/trafficserver,persiaAziz/trafficserver,rahmalik/trafficserver,chitianhao/trafficserver,chenglongwei/trafficserver,clearswift/trafficserver,rahmalik/trafficserver,dyrock/trafficserver,chenglongwei/trafficserver,SolidWallOfCode/trafficserver,SolidWallOfCode/trafficserver,dyrock/trafficserver,davidbz/trafficserver,persiaAziz/trafficserver,clearswift/trafficserver,SolidWallOfCode/trafficserver