add getAssignableSlots method to Cluster and improve blacklisting logic
add getAssignableSlots method to Cluster and improve blacklisting logic

taoguan/storm-1,roshannaik/storm,sakanaou/storm,hmcl/storm-apache,kamleshbhatt/storm,lcp0578/storm,lcp0578/storm,jamesmarva/storm,ferrero-zhang/storm,Frostman/storm,3manuek/storm-1,d2r/storm-marz,srishtyagrawal/storm,sakanaou/storm,chrismoulton/storm,raviperi/storm,ujfjhz/storm,gongsm/storm,roshannaik/storm,revans2/storm,Crim/storm,hilfialkaff/storm,carl34/storm,rahulkavale/storm,metamx/incubator-storm,0x726d77/storm,konfer/storm,allenjin/storm,knusbaum/incubator-storm,kevinconaway/storm,erikdw/storm,adityasharad/storm,knusbaum/incubator-storm,allenjin/storm,kevinconaway/storm,hmcl/storm-apache,kishorvpatil/incubator-storm,mesosphere/storm,kishorvpatil/incubator-storm,praisondani/storm,Aloomaio/incubator-storm,gongsm/storm,jamesmarva/storm,srdo/storm,Frostman/storm,ujfjhz/storm,allenjin/storm,Frostman/storm,pczb/storm,revans2/storm,hmcc/storm,roshannaik/storm,hmcl/storm-apache,praisondani/storm,pczb/storm,raviperi/storm,kamleshbhatt/storm,revans2/incubator-storm,knusbaum/incubator-storm,3manuek/storm-1,nathanmarz/storm,kishorvpatil/incubator-storm,cluo512/storm,mesosphere/storm,nathanmarz/storm,Aloomaio/incubator-storm,hmcl/storm-apache,srishtyagrawal/storm,ujfjhz/storm,elancom/storm,lcp0578/storm,kishorvpatil/incubator-storm,0x726d77/storm,F30/storm,srishtyagrawal/storm,Crim/storm,kevpeek/storm,d2r/storm-marz,metamx/incubator-storm,0x726d77/storm,hmcl/storm-apache,chrismoulton/storm,Crim/storm,raviperi/storm,revans2/incubator-storm,gongsm/storm,sakanaou/storm,cluo512/storm,0x726d77/storm,F30/storm,kevpeek/storm,kishorvpatil/incubator-storm,ujfjhz/storm,raviperi/storm,praisondani/storm,adityasharad/storm,ujfjhz/storm,cherryleer/storm,hmcc/storm,kevpeek/storm,hmcl/storm-apache,taoguan/storm-1,d2r/storm-marz,ujfjhz/storm,Crim/storm,revans2/incubator-storm,nathanmarz/storm,0x726d77/storm,erikdw/storm,jamesmarva/storm,cherryleer/storm,gongsm/storm,carl34/storm,3manuek/storm-1,chrismoulton/storm,cherryleer/storm,kevinconaway/storm,Aloomaio/incubator-storm,erikdw/storm,sakanaou/storm,ujfjhz/storm,d2r/storm-marz,ferrero-zhang/storm,allenjin/storm,Aloomaio/incubator-storm,sakanaou/storm,carl34/storm,srdo/storm,Aloomaio/incubator-storm,pczb/storm,elancom/storm,hmcc/storm,srishtyagrawal/storm,praisondani/storm,roshannaik/storm,raviperi/storm,erikdw/storm,konfer/storm,revans2/storm,srishtyagrawal/storm,cluo512/storm,Crim/storm,kamleshbhatt/storm,konfer/storm,hmcc/storm,metamx/incubator-storm,erikdw/storm,carl34/storm,kevinconaway/storm,ferrero-zhang/storm,srdo/storm,chrismoulton/storm,rahulkavale/storm,erikdw/storm,taoguan/storm-1,konfer/storm,hilfialkaff/storm,mesosphere/storm,adityasharad/storm,mesosphere/storm,kevpeek/storm,jamesmarva/storm,revans2/storm,kamleshbhatt/storm,srdo/storm,roshannaik/storm,F30/storm,knusbaum/incubator-storm,kishorvpatil/incubator-storm,praisondani/storm,d2r/storm-marz,cluo512/storm,taoguan/storm-1,F30/storm,elancom/storm,kevinconaway/storm,knusbaum/incubator-storm,carl34/storm,hilfialkaff/storm,pczb/storm,nathanmarz/storm,Aloomaio/incubator-storm,kishorvpatil/incubator-storm,knusbaum/incubator-storm,lcp0578/storm,F30/storm,pczb/storm,knusbaum/incubator-storm,sakanaou/storm,cluo512/storm,ferrero-zhang/storm,mesosphere/storm,adityasharad/storm,kevpeek/storm,Crim/storm,ferrero-zhang/storm,metamx/incubator-storm,0x726d77/storm,raviperi/storm,chrismoulton/storm,elancom/storm,F30/storm,hmcc/storm,hilfialkaff/storm,carl34/storm,srishtyagrawal/storm,cherryleer/storm,rahulkavale/storm,rahulkavale/storm,hmcc/storm,roshannaik/storm,kamleshbhatt/storm,revans2/storm,erikdw/storm,srdo/storm,3manuek/storm-1,kevpeek/storm,cluo512/storm,hmcl/storm-apache,srdo/storm,mesosphere/storm,allenjin/storm,Frostman/storm,0x726d77/storm,hilfialkaff/storm,kamleshbhatt/storm,srdo/storm,carl34/storm,revans2/incubator-storm,revans2/incubator-storm,raviperi/storm,taoguan/storm-1,cluo512/storm,metamx/incubator-storm,Frostman/storm,kevinconaway/storm,F30/storm,kamleshbhatt/storm,pczb/storm,jamesmarva/storm,Aloomaio/incubator-storm,nathanmarz/storm,adityasharad/storm,elancom/storm,adityasharad/storm,konfer/storm,3manuek/storm-1,adityasharad/storm,lcp0578/storm,cherryleer/storm,hmcc/storm,Crim/storm,gongsm/storm,srishtyagrawal/storm,kevinconaway/storm,rahulkavale/storm,pczb/storm,sakanaou/storm,roshannaik/storm,kevpeek/storm