add triangleBorder mixin
add triangleBorder mixin

tomaszdurka/CM,tomaszdurka/CM,vogdb/cm,mariansollmann/CM,fauvel/CM,alexispeter/CM,fvovan/CM,tomaszdurka/CM,alexispeter/CM,fauvel/CM,mariansollmann/CM,vogdb/cm,christopheschwyzer/CM,cargomedia/CM,christopheschwyzer/CM,zazabe/cm,cargomedia/CM,fvovan/CM,fvovan/CM,zazabe/cm,alexispeter/CM,vogdb/cm,christopheschwyzer/CM,vogdb/cm,tomaszdurka/CM,mariansollmann/CM,tomaszdurka/CM,fvovan/CM,njam/CM,christopheschwyzer/CM,fauvel/CM,fauvel/CM,njam/CM,mariansollmann/CM,alexispeter/CM,vogdb/cm,njam/CM,zazabe/cm,fauvel/CM,njam/CM,cargomedia/CM,njam/CM,cargomedia/CM,zazabe/cm