Adding backbone.modal js and css

Signed-off-by: José Luis Di Biase <josx@interorganic.com.ar>
Adding templates for modal windows

Signed-off-by: José Luis Di Biase <josx@interorganic.com.ar>
Moving js alert,confirm,prompt to backbone views

Signed-off-by: José Luis Di Biase <josx@interorganic.com.ar>