Revert "duplicatedSelectors: special handling for @font-face (#52)"

This reverts commit 0c3ee3d03024756ee436e6770e0c0a2a2e4dcdb0.
Use css instead of css-parse module (#25)

+ port duplicated rules to use a new event
sass: update test case - errors detection
Report line and column in offenders
Update the position for each declaration
duplicated: do not report position to the offenders
Merge pull request #55 from macbre/report-position

Report line and column of CSS "issue" in offenders