Enabled ShellCheck rules:
SC1087
SC2001
SC2004
SC2005
SC2006
SC2016
SC2028
SC2048
SC2066 (note that IFS already contains only a line feed)
SC2116
SC2166
SC2181
SC2206
SC2207
SC2230
SC2236
Zcash: Only the changes that applied to the versions of the scripts we have.