Update README.md
Update README.md
new field, acc_time, added to record 'fun_calltree'.
added time percentage (lifetime of function/life time of process) to nodes in callgraph.
removed unused variable WaitTimes; added read_concurreny option to some ets tables; added acc_time to fun_calltree.
Merge branch 'master' of git://github.com/huiqing/percept2
added total rq_history info to artifical processes.
bugfix to the generation of callgraph slices.
fixed type errors.
 bug fix to formatting nodes in the graph.
change of function interface
doc updated.
removed case studies
removed the 'summary report' item.
removed the 'summary report' item from menu.
added more conditions to the Match specification in order to reduced the amount of data returned; handled the case when there is no trace data record for the concurrency overview page.
interface to the profile function is changed to allow more options.
changes made to follow the changes to percept2:profile/2/3.
fixed the problem with consolidation.
record the arity instead of arguments of process entry functions..