* Simplify EINTR/ECANCEL error handling
1. Add semaphore uninterruptible wait function
2 .Replace semaphore wait loop with a single uninterruptible wait
3. Replace all sem_xxx to nxsem_xxx
* Unify the void cast usage
1. Remove void cast for function because many place ignore the returned value witout cast
2. Replace void cast for variable with UNUSED macro
Fixed coding standard error in several files. Use of while( is incorrect; a space is required between while and (. Also ran tools/nxstyle and fix thoses complaints as well in most files.
Changes to comply with coding standard. Mostly focused on files with missing space after keyword in if(, switch(, and for(. Offending files also got changes to comply with tools nxstyle. If there were logs of nxstyle complaints, the file also got a taste of tools/indent.sh. Still need to fix occurrences of while( with missing space. There are a lot of them.
Entropy pool gathers environmental noise from device drivers, user-space, etc., and returns good random numbers, suitable for cryptographic use. Based on entropy pool design from *BSDs and uses BLAKE2Xs algorithm for CSPRNG output.
Patch also adds /dev/urandom support for using entropy pool RNG and new 'getrandom' system call for getting randomness without file-descriptor usage (thus avoiding file-descriptor exhaustion attacks). The 'getrandom' interface is similar as 'getentropy' and 'getrandom' available on OpenBSD and Linux respectively.
