add design notes for modifying driver to be distributed
Added support for catching exceptions from OperationHandlers in main WorkloadRunner thread
Moved Spinner scheduling into OperationHandler (still in WorkloadRunner too) to get more accurate scheduling
Convert Operation stream into OperationHandler stream before running benchmark, to reducing latency during runtime
Merge branch 'new_branch_name'

Conflicts:
	src/main/java/com/ldbc/driver/OperationHandler.java
	src/main/java/com/ldbc/driver/runner/CompulsoryStartTimeOperationSchedulingPolicy.java
	src/main/java/com/ldbc/driver/runner/WorkloadRunner.java
	src/test/java/com/ldbc/driver/temporal/TimeTest.java
add ConcurrentErrorReporter class to enable error reporting between main and child threads
add FeedbackOperationSchedulingPolicy, which writes to a ConcurrentErrorReporter injected from main thread
modify all child threads to use ConcurrentErrorReporter class and pattern - requires more testing
Merge branch 'master' of https://github.com/ldbc/ldbc_driver

Conflicts:
	src/main/java/com/ldbc/driver/metrics/OperationMetrics.java
	src/main/java/com/ldbc/driver/runner/WorkloadRunner.java
use milliseconds for runtime measurements
save runtimes to file

to be used as gnuplot input