removed unused *_resourceCache() functions
added support for updating NODES list safely
fixing corner cases in NODES handling
Merge branch 'maint/4.0/testing' into dev/dmitrii/maint-4.0
added comments to recent code for NODES ingress
ran indent over back-end codebase
bumping up open files limit in NC init script

fixes EUCA-9557
Merge branch 'maint/4.0/testing' of git+ssh://git.eucalyptus-systems.com/eucalyptus into maint/4.0/testing