Update with latest CLI options and note about rubyracer dep
Additional note regarding headers
Update ext/libv8/arch.rb

Check for arm. Compile still fails with
ERROR: Binary compiled with -mfloat-abi=hard but without -DUSE_EABI_HARDFLOAT
(raspberry pi)
Ensure all files in binary package are world-readable
Specify license in gemspec

Makes it possible to use tools like https://github.com/pivotal/LicenseFinder
Make arch detection more readable
Avoid compilation failure in snapshot
Tweak make flags to allow arm compilation
Do not display an error when gmake is not present
Isolate printing of build info in a method

Conflicts:
	ext/libv8/compiler.rb
	ext/libv8/paths.rb
Avoid false positive for x86_64
Use Gem::Package in under Ruby 2

This commit fixes #86