Fixed bug where authhash/authkey buffer was duplicated due to array syntax
Added try catch around js execution to avoid killing cef thread
Changed zeroBuffer to use memset and added tests to make sure it does what its meant to do
Fixed item handle to have recursive mutex and use lock guard
Fixed race cond in canceling validation
Fixed canceling validation to be quicker
Fixed gcc complaining about narrowing type
Merge pull request #776 from lodle/ThreadFixes

Thread fixes