REAL, WORKING and HEAVILY COMMENTED code for ENCODING *AND* DECODING using the Base 64 method!

This code can encode strings using the Base 64 method, and also decode the encoded strings. This is PROBABLY useful for a few things, but the only use I know for it is sending E-Mails with file attachments. Wow, it looked so evilly terribly horrible in the browser, I just HAD to upload a ZIP file with the same contents! Sorry!