Feature/query

* cherry-pick from master branch.

* cherry-pick from master branch. c23043c0Co-authored-by: NShuduo Sang <sdsang@taosdata.com>

Co-authored-by: NShuduo Sang <sdsang@taosdata.com>

* [TD-3913]<fix>: mips compile support.

* [TD-3913]<fix>: mips64 support.

* fix osSignal.c

* fix tcrc32c.c

* fix cmake.

* fix osInc.h

* fix gcc 4.8 compile error.

* fix clang compile error.
Co-authored-by: NShuduo Sang <sdsang@taosdata.com>

* merge with develop branch.

change query/tests/CMakeLists.txt to allow unused function and variable.

* refactor data generating.

* refactor.

* refactor.

* refactor.

* refactor.

* refactor

* add prepare stmt function.

* refactor get rand timestamp.

* fix windows compile error.

* copy logic of generate data for stmt.

* insert data basically works now.

* fix windows compile issue.

* [TD-4068]<feature>: taosdemo stmt interface.

stb batch insert works.

* [TD-4068]<feature>: taosdemo support stmt.

normal table insert works.

* [TD-4068]<feature>: taosdemo support stmt.

interlace write works.

* add compile macro to make taosdemo same with master branch.

* fix clang compile error.
Co-authored-by: NShuduo Sang <sdsang@taosdata.com>

[TD-3950]cache last

[TD-1920]add mnode_bak and mnode_tmp dir exist check when start up

* merge with develop branch.

change query/tests/CMakeLists.txt to allow unused function and variable.

* refactor data generating.

* refactor.

* refactor.

* refactor.

* refactor.

* refactor

* add prepare stmt function.

* refactor get rand timestamp.

* fix windows compile error.

* copy logic of generate data for stmt.

* insert data basically works now.

* fix windows compile issue.

* [TD-4068]<feature>: taosdemo stmt interface.

stb batch insert works.

* [TD-4068]<feature>: taosdemo support stmt.

normal table insert works.

* [TD-4068]<feature>: taosdemo support stmt.

interlace write works.
Co-authored-by: NShuduo Sang <sdsang@taosdata.com>

Co-authored-by: NShuduo Sang <sdsang@taosdata.com>

[TD-4387] <docs>: fix broken link to server config doc.

add cache last null columns feature

Docs/update latest feature

Feature/m2d