[#8] Fix onload event handler.
Fix crash bug when there is no stickies.
Sweep previous stickies, then load stickies.
Add dist/* to .gitignore
Update maxVersion: 12.0 -> 30.0
Update version 0.4.3
[#8] Use e.target as content.document
Fix makefile
Fix sticky css
Merge pull request #14 from kumabook/8-not-appear-stickies

Fixed #8