Fix some problems with gii bootstrap default template

I had some minor problems with the templates used in the gii Bootstrap generator. 

Here are my fixes in the bootstrap gii default template - hope it's useful:
- added some closing echo ?> (solves some "Parse error: syntax error, unexpected '<' ")
- added a missing echo (adds missing save/create Button under form)
- changed TButton in TbHtml::SubmitButton (solves "Alias "bootstrap.widgets.TbButton" is invalid. Make sure it points to an existing PHP file and the file is readable.")
- changed TbDetailView in CDetailView (as suggested in https://github.com/Crisu83/yiistrap/issues/32#issuecomment-19688131 - solves "Alias "bootstrap.widgets.TbDetailView" is invalid. Make sure it points to an existing PHP file and the file is readable.")