Make clear that cbmc version of charAt and substring do not throw OutOfBound TG-1808#1665

thk123 merged 5 commits intodiffblue:developdiffblue/cbmc:developfrom

romainbrenguier:bugfix/string-out-of-bound#TG-1808romainbrenguier/cbmc:bugfix/string-out-of-bound#TG-1808Copy head branch name to clipboard