update README
change links in README
Update README.md
Merge pull request #15 from PerryPan/master

readme improvment
fix some grammer and typo problem, added new description of proimise
include LICENSE file
LICENSE
fix time display bug due to the timezone parse problem, disable option page
add complete and ignore feature
use js date instead of moment in bg
update screenshot
Merge pull request #22 from PerryPan/master

初步加入完成和忽略功能
move localStorage store to a service, using filter to hide deadlines
fix spelling error
rename courserStorage to alfredStorage
move all localStroage manipulation to alfredStorage
fix sign in bug, add update removed deadlines feature and use checkbox
fix spelling error
include node_modules in gitignore
Merge pull request #23 from PerryPan/master

修复在用户没有sign in情况下的bug ，将button改为checkbox，以及加入更新removedDeadlines