1. Support cygwin by '--cygwin64=on'
2. Detect cygwin automatically.
3. Disalbe sanitizer, srt and srtp with openssl.
4. Disable multiple threads, use single threads.
5. Support utest for cygwin64.
6. Query features for windows by API.
7. Disable stat APIs for cygwin.
8. Use ST select event driver.
Co-authored-by: wenjie.zhao <740936897@qq.com>
1. Replase ln by cp for windows.
2. Refine OS and CPU arch detecting.
3. Support configure from any directory by `SRS_WORKDIR`.
4. Support output to any directory by `SRS_OUTPUT`.
5. Disable sanitizer for gperf.
6. Use parallels build for make.
7. Refine bash variable check.
* fix annotation spell failed
* RTC to RTMP using SenderReport to sync av timestamp
* update pion/webrtc versio from v3.0.4 -> v3.0.13, auto config sender/receiver report
* Add rtc push flv play regression test
* Add unit test of ntp and av sync time
* Take flag CXX to makefile of utest
* Add annotation about rtc unit test
* Fix compiler error in C++98
* Add FFmpeg log callback funciton.