amlgrep fix ^, $, and \\n sanitizing code
Fix regex sanitizer for bash-3.x (RHEL5)
Fix \n in regex sanitizer
amlgrep: use quoted literal for =~ regex
Use case-statement instead of [[ =~ ]]

Bash's =~ seems to have variety of version incompatiblities.
Looks to me it's not just Bash's versions, but also
incompatiblity of underlaying regex library.
Merge branch 'awk-sanitize-regex'

fix '\n' and '^' conversion for --rs option in all
MacOSX/Ubuntu/RHEL5, bash3/4