Merge pull request #89 from fengjingchao/master

fix README
fix execution

clear sccIndex and sccLowlink when aborting the execution,
so that we won't miss that instance later
test

add test script
Merge pull request #90 from yifan-gu/persistent

Persistent
Merge pull request #91 from go-distributed/proj3

Merge into master
fix and test

in execute, even resolveConflict fails, we should try to execute
anyway, because there may be a complete scc in sccResult

add test.sh and build.sh
Merge pull request #92 from yifan-gu/persistent

fix and test
Merge pull request #93 from go-distributed/master

Merge pull request #91 from go-distributed/proj3
Merge pull request #94 from go-distributed/proj3

Merge into master
update readme
Merge pull request #95 from yifan-gu/proj3

update readme
Merge pull request #96 from go-distributed/proj3

final project readme
Merge pull request #97 from go-distributed/master

Master
chore

send pre-accept instead of accept for no-op,
and make no-op conflict with every other command before
Merge pull request #98 from yifan-gu/proj3

chore
Merge pull request #99 from go-distributed/proj3

Merge into master
Merge pull request #100 from go-distributed/master

Merge pull request #99 from go-distributed/proj3
Merge pull request #101 from go-distributed/proj3

Merge pull request #100 from go-distributed/master