Fix find PerformanceCounterInstance

It does not always 'startswith' - running as application or debugging on my win81
pc the Instancename is:
'Raven.Server.vshost/1-UxBsU-C:\Users\SteinArild\Source\Repos\RavenDb\build\Database'
trying to match uniquePrefix = '1-UxBsU'
corrected spelling(utiliti => utility)
Merge branch 'RavenDB-1631' of github.com:ppekrol/ravendb
Merge branch 'master' of https://github.com/ghuntley/ravendb
Code convention
minor
Merge pull request #559 from ppekrol/copyright-fix

copyright-fix
Merge branch 'master' of github.com:ayende/ravendb
Try to fix RavenDB-1633
RavenDB-1660 Facetquery performance degraded after build 2806
Minor fixes to previous commit
Adding logging for facet prewarming
Fixing default operator not considered when using select fields
Merge branch 'master' of https://github.com/fitzchak/ravendb
Fixing auth in SL
Fixing bad handling of requests in SL when they didn't return any json content
Minor
Properly filtering out already deleted items by prefetching behavior - there was a bug when deleted etag was greater that an etag of a checked document
Merge branch 'indexing-skips-deleted-docs' of github.com:arekais/ravendb
Adding missing filtering of replicated documents by the prefetcher