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 inside my ide

it looks like the expected behaviour to me

[Gimbardo]

sorry for this ping @mame
I was wondering if anything is missing from this PR, since this looks pretty stale. Ask me anything if you have any request.
(I hate my monkey patches, and would like to remove them from other projects :P )