Update HISTORY for version 0.8.0.
Update HISTORY for version 0.8.0.

GerHobbelt/remark,programath/remark,noname007/remark,FabioBeneditto/remark,kwangkim/remark,linkabi9/sdjs20150309directives,kwangkim/remark,jonathanpberger/design-testing,jonathanpberger/design-testing-pairing,lucamaraschi/pressenter,imouren/remark,jonathanpberger/points-estimation-velocity,doctoryes/remark,ghoshbinayak/nodeppt,linkabi9/sdjs20150309directives,tkraak/remark,emi80/remark,mariojp/remark,programath/remark,jonathanpberger/design-testing-pairing,jonathanpberger/design-testing-aed,jonathanpberger/mce-test,tkraak/remark,reyhansofian/remark,reyhansofian/remark,shigemk2/remark,jonathanpberger/dark-design,jonathanpberger/points-estimation-velocity,saadatqadri/remark,bytezen/remark,jeromecc/rmll2015madagascar,xiaoking/remark,gnab/remark,FabioBeneditto/remark,bkeepers/remark,bkeepers/remark,JPry/remark,shigemk2/remark,mariojp/remark,tripu/remark,lucamaraschi/pressenter,GerHobbelt/remark,jonathanpberger/dark-design,JPry/remark,tripu/remark,doctoryes/remark,emi80/remark,noname007/remark,imouren/remark,jeromecc/rmll2015madagascar,xiaoking/remark,saadatqadri/remark,jonathanpberger/design-testing-aed,bytezen/remark,tilast/service-objects,tilast/service-objects,gnab/remark,ghoshbinayak/nodeppt