More python detection fixes

1. Fix path system python detection on windows (using "where" might return multiple lines)
2. Move python path detection out of system_python (should handle all cases, not just system_python)
3. Poll server process for 100ms - this catches proc crashes without the need for cross platform dependency such as psutil
4. Detect when proxy is not set (i.e failed running server) when running "check_syntax" method

These further prevent client from talking to a dead server (which causes for multiple miss calls)