Correct/go back trace overlap (vesoft-inc#2203)

* Fix the go back trace overlap.

* Fix some typo. And unnecessary copy by reference.

* Fix the note comment.

* Add a case to cover the issue that back tracker will overlap the dst, src in current step.

Co-authored-by: jude-zhu <[email protected]>

Revert the 2087 workaround. (vesoft-inc#2168)

RC4 Cherrypick vesoft-inc#2031 vesoft-inc#2042 vesoft-inc#2025 vesoft…

…-inc#2013 vesoft-inc#2038 (vesoft-inc#2051)

* remove bigint because we dont support it (vesoft-inc#2031)

Co-authored-by: dutor <[email protected]>
(cherry picked from commit 3423df1)

* fix crash (vesoft-inc#2042)

Co-authored-by: dutor <[email protected]>
(cherry picked from commit eea7407)

* Sampling apply to all edges starting from a vertex. (vesoft-inc#2013)

* Sampling from all edges.

* Update test for sampling multi edges.

* Testing both inbound and outbound.

* Fix clang compiling problem.

* Update the sampling.

Co-authored-by: dutor <[email protected]>
(cherry picked from commit 8810ecc)

* Fix the error when vertex/edge not exist if update. (vesoft-inc#2025)

* Fix the error when vertex/edge not exist if update.

* Optimize the atomic error logical.

* Fix one alignment.

Co-authored-by: dutor <[email protected]>
(cherry picked from commit 9fc4e7f)

* Correct issue 2009 which the timestamp default value for edge not treat. (vesoft-inc#2038)

* Correct issue 2009 which the timestamp default value for edge not treat.

* Add the cover cases.

* Fix one typo.

Co-authored-by: dutor <[email protected]>
(cherry picked from commit 4aa9217)

Co-authored-by: flyingcat <[email protected]>
Co-authored-by: laura-ding <[email protected]>
Co-authored-by: CPWstatic <[email protected]>
Co-authored-by: Shylock Hg <[email protected]>

Report error if schema null. (vesoft-inc#1700) (vesoft-inc#1711)

Co-authored-by: dutor <[email protected]>
(cherry picked from commit 8a9daec)
(cherry picked from commit 65364c2)

Co-authored-by: CPWstatic <[email protected]>

Add StatsManager in graphd (vesoft-inc#1301)

Issue vesoft-inc#1203 fixed the possible crash. (vesoft-inc#1204)

The crash is caused by the use of two meaningless DCHECK in debug mode.

Fixed ConfigTest occasional failure (vesoft-inc#770)

readme delete email (vesoft-inc#374)