git ignore bin folder (for rails 4 dev usage)
Easier extending default show page

I would like to add few fields to show page, but keep the defaults.

Passing block to `default_main_content` would make it use defaults + block.
fix site title of namespaces
test yielding block of default_main_content
correct usage of generator source_root
Merge pull request #3376 from timoschilling/generator_source_root

correct usage of generator source_root
Merge pull request #3365 from timoschilling/fix_namespace_site_title

fix site title of namespaces
Merge pull request #3355 from timoschilling/gitignore

git ignore bin folder, to support binstubs
Merge pull request #3358 from mikz/patch-1

Easier extending default show page