fix some typos

Merge branch 'sign-it'

Merge pull request #23 from pmario/addon-signed

Addon signed

Version: 0.3.5

V 0.3.3 signed by Mozilla - first official AddOn listed

Merge pull request #15 from pmario/addon-signed

make TWclassic work again

Merge pull request #14 from pmario/addon-signed

Addon signed

Merge pull request #7 from pmario/addon-signed

Addon signed

Merge pull request #4 from pmario/add-tw-classic

Add tw classic

modify id, so ff accepts it