added bind_tcp.rb
Added a sample stage + updated bind stager.
Added reverse stager.
Moved dupandexecve.rb to shell.rb due to pull request coments.
Made changes as suggested, forgot to remove exit() after testing was complete.
Changed reverse payload as suggested.
Add small fixes for stagers
Add commented source code for stagers and stage
Fix author name
Merge pull request #1 from jvazquez-r7/arm_stagers

ARM stagers cleanup
Land #1879, @dcbz ARM stagers