Bootstrap-ify LESS and CSS

I've refactored the LESS/CSS so it closely matches Bootstrap.

- Core classes are now named `tm-tag` (previously `myTag`) and `tm-input` (previously `myTagManager`)
- Add support for Bootstrap like semantic color and size classes
- Bootstrap-style remove icon (× character instead of x)
- Update JS file to match new names
- Remove `&nbsp;` chars from inside tag, and replace with remove icon margin
- Tags in default size now align perfectly with the Bootstrap input control. The form spacing no longer tweaks when you add your first tag.
- Size classes match button heights. Tags of different sizes are vertically centered.
- Better usage of LESS variables
- Regenerate CSS from LESS
- Despite all the added functionality, the new CSS is **6 lines shorter** than the current CSS file (101 versus 107)

![tag-styles](https://f.cloud.github.com/assets/27655/520826/d6aa924e-bf4a-11e2-94b5-33d3340801ac.png)

In addition, I've enhanced the Javascript to interpolate the tag class from the input class, for example `<input class='tm-input tm-input-success tm-input-small'/>` will cause all tags to have classes `tm-tag-success` and `tm-tag-small`. This avoids users having to use the `tagClass` option (`tagClass` remains fully supported)

Note that the base color of tags is now gray, in keeping with Bootstrap standards.