Code cleanup and get helpers in sync with Bootstrap 3.2

Breadcrumb Helper
* Breadcrumbs don't need to specify a `divider` anymore. This is now handled in CSS in Bootstrap 3.
* Bootstrap 3 now recommends an `<ol>` tag for breadcrumbs.

Glyph Helper
* Glyph code comment and README example needed update. Also, Bootstrap 3 recommends a `<span>` over an `<i>` tag for glyphs.
* Can now output more than one glyph at a time if desired.
* Added tests for `glyph` method.

Flash Helper
* Flash helper needs to not assume its inputs are html-safe, they may not be. Proper use of `safe_concat` removes the security hole.
* Even worse was the security hole introduced by using `eval` on the url. Using `send` works just as well.
* Bootstrap 3 recommends a `<button>` tag for the close control for compatibility with mobile browsers.
* Updated tests.
* Now lets unknown alert type pass through as-is. This allows custom types/classes to be used at the user's discretion.