merge from master a726463

  findDirectAgentToLoad ordered by clusterId

bug 7830: fixed issues with 300 limit on listing vm instances.

bug 7295: seems like one agent attache is removed twice

status 7295: resolved fixed

bug 7251: block IE6 from accessing /client/console

status 7251: resolved fixed

bug 7191: can't use macro errno.EEXIST here, use 17 instead

status 7191: resolved fixed

update version to 2.1.5

bug 6607: return true for nfs

status 6607: resolved fixed

one more fix about deletestoragepool

set uuid of storagepoolvo to null

Cleaned up Storage capacity Global Lock code that no longer in use.

Fixed assertion error related with transaction usage in StatsCollecto…

…r and AlertManagerImpl