Defines functions for each as autoload functions. I need to look into
weather it would be better to have this as a local function in a plugin.
The function for url encoding was taken from vim-unimpared:
https://github.com/tpope/vim-unimpaired
I don't need all the functionality it provides
The function for base64 encoding was taken from vim-base64:
https://github.com/christianrondeau/vim-base64
although I use it with mappings in the vim-unimpared style
[b and ]b base64 encode and decode respectively
[u url encodes characters that are normally encodede in a url
[U url encodes all characters
]u and ]U both urldecode all encodede characters
Jonathan Hodgson