Sign a Certificate Signing Request in XS.

Changes for 0.12

• 150a974 Increment version for release
• 61978d5 Fix incorrect case for PERL_VERSION
• 9f7fafe Change tabs to spaces - no code changes
• 10d3a65 Fix issue with more openssl versions
• 9eccdd7 (tag: 0.11, origin/main) v0.11