improvements for form family snippets

Some abbreviations that I miss.

I think is also a good idea add check : input:checkbox and radio : input:radio. check:d and radio:d for disabled variations too.
Assume that we are working with html5 is not a good idea.
Fixing and improving fieldset, select and button disabled abbreviations
Merge pull request #189 from leobetosouza/patch-4

improvements for form family snippets