Update version of tunesviewer to a the 1st pre-release.

Note that, as a string, the new version (1.4.99.0) is lexicographically
smaller than the next "final" release (1.5) and, therefore, a simple
comparison with Python's `<=` works as we want.

With this small change, we can actually tag this pre-release in the git-repo
and have a saner Debian packaging (at least), especially when using
`git-buildpackage`.

It may help with other systems, like RPM too, but I don't know enough about
them to make informed assertions.

Signed-off-by: Rogério Brito <rbrito@ime.usp.br>
Remove some unused modules found by pyflakes.
TunesViewer: Don't overwrite module with the same name.
Updated constants.
Set Home URL
Possible improvement
Update strings and attempt improve Javascript.js
Improved tests file.
Fix parsing.
Update help url since SF hosted apps will be gone later.
Changes to About and Help URL for 1.5.
Update tests.
Fixed some glitches in webview.
Fixed Javascript and subscribe.
Define the function before it's used.
Set Github issues url, fixed a bug, file always downloading.
Fix extension for some files downloaded from webview.
Fix subscribe toolbar-button in some cases.
Removed unnecessary console.logs.
Removed unnecessary console.logs.