Add -i to `procs find`; Minor fixes

Basically:

• Add -i flag to procs find to force pattern insensitivity { just by prefixing each pattern with "(?i)" as per lib/impure/nre.nim documentation. Seems to work fine. }
• Make pw less chatty (only ^C not default Nim message), but still exit 130 in case there is some pw patterns && shell construct.
• For >=100% just show integer percentage; 3 significant figures is plenty.
• Ensure data is flushed to stdout before sleeping in differential mode.
• Do not total syscall IO & blockdev IO for %<,%> (too often doubles IO).
• Various updates to sample config and compile-time warning/error fixes.
• Also added release notes for version 0.3.0.