Now handles login errors
Fixed serious bug; now actually uploads file contents instead of the names of the files
Fix extremely embarrassing bug thanks to @doomrobo

Bug causes sfs to upload a the filename as the image data. The problem
is that we're supplying filename as an argument to the method that does
the uploading -- but the argument should be the image data.

This commit will fix this issue by changing having the upload function
do the data reading.
Removed extra line
Merge pull request #3 from doomrobo/master

Login errors are handled (and not saved) and can now upload file contents (not just filenames)
Handle relative paths correctly
Update comments in API file
Add @doomrobo to authors