Different binary states for different subspecs of the same pod leads to many problems

```ruby
target 't' do 
    pod 'A/sub1' , :binary => true
    pod 'A/sub2'
end
```
The preuilt A.framework will contain no sub2 content.

```ruby
target 't' do 
    pod 'A/sub1' , :binary => true
    pod 'A/sub2'
end
target 'p' do 
    pod 'A/sub3' , :binary => true
end
```
It will crash on prebuilt stage of a second pod install.
