add a Launcher for start the engine
review the working flow: 
laucher->feedfetcher->pagefetcher->pagewasher->post
change @id from 'link' to 'key' in Subscribe.java Entity

Signed-off-by: luchunwei <luchunwei@gmail.com>
fix /launcher servlet mapping error in web.xml

xercesImpl.jar in Xerces-J-bin.2.9.1.zip is working with ROME, 2.11.0 is
not working