misc changes

README updates

corrected parens

added filenames back, instead of 'from_file' and 'to_file'

when comparing two selections, ignore indent. I might add this to oth…

…er diff commands in the future

added 'sublime-menu's. thanks go to (bzx)[https://github.com/bzx] for…

… the feature request

minor fix

rm 'Diff with Saved' if file is not dirty

added example keymap file

get content from ST2 when diffing from tab