Issue #55: add unit tests for fetch_icon
Merge pull request #56 from yurenju/unittest

Issue #55: add unit tests for fetch_icon r=gasolin
Issue #59: Refactoring & adding unit tests for preload.py
Merge remote-tracking branch 'upstream/master'
Merge pull request #60 from yurenju/refactoring

fixed Issue #59: Refactoring & adding unit tests for preload.py
Merge pull request #57 from gasolin/master

issue #54: use single quote for consistency r=yurenju
Merge remote-tracking branch 'upstream/master'