Update, rename and clean up various scripts Rename contrib/tools/chkfmt to contrib/tools/chkfmt.sh; refactor: * Increase the max line length for contrib/**/*.[ch] from 96 to 100. * Set the max line length for ci_*.sh to 100. * Use `basename $0` instead of the hard-coded script name. * Update comments. Remove contrib/tools/reindent. For automated code formatting, including indentation, we need a robust solution. Add an empty line after the hashbang line in all scripts. Remove the "last changed" version info from comment headers. (The version control system maintains this information automatically.)