Update version number in README

The README mentions the 0.4 release has been submitted for review, this
is outdated, it has been accepted and is now the version you can
download from the Firefox add-ons site.
Remove unused files

The `doc`, `locale` and `test` directories only contain placeholder
files, this makes it harder for a new maintainer to understand the
structure of the project so I simply removed them. Removed the
`package.json.backup` as well, it's a git repository, no need to keep
`.backup` files.
Whitespace

Remove trailing whitespace
Replace all tabs with spaces for consistency
Remove execution permissions from files

Some files had the execution permissions flag set, some had not. This
commit removes that permission from all of them.
Merge pull request #19 from cimm/documentation

Update version number in README
Merge branch 'cleanup' of github.com:cimm/tosdr-firefox into cimm-cleanup
Merge branch 'cimm-cleanup'