acheive the web page downloading module
add SSL certification verify, fix no file name failure bug
add URL unresolveable exception
add log recorder
create HTML href tag extractor
fix bug is saving HTML
refine HTML href attractor filter pattern
change thread pool size
fix forgotten varible name
fix save file bug
add link record table in database
Web Crawler is work! Although still have small flaws need to be improve
Update gitignore File