Add missing command to the build instructions in the README.
Map armv6l host architecture to arm.
Use startswith approach so it also catches other versions of architecture.
Merge pull request #428 from Kami/arm_build_fixes

Fixes for ARM build
Merge pull request #427 from Kami/update_readme_build_instructions

Add missing command to the build instructions in the README
Update openssl submodule to include arm changes.