Aliases for every method

[Gimbardo]

Basically, I hated how I had to write Base64.encode64, it felt so redundant, so I created aliases for every method of this library, to allow for a more simple "Base64.encode"

I also added tests for what I wrote, and "gemspec" to Gemfile to allow bin/console to load the gem you are working on, and not the one installed in the system

[Gimbardo]

is this valid? @hsbt

[mame]

Can you confirm if this patch works well for rdoc? I am not sure if rdoc can handle these aliases as class methods but not instance methods.

[Gimbardo]

@mame created the requested tests
for rdoc, it looks like this inside the docs:
.
and like this for the code

it looks like the expected behaviour to me

[Gimbardo]

@mame is anything missing?