[PlatformProxy] Raise an error when calling platform=

[Docs] Clarifies deprecated methods in docs

[Platform] Add convenience methods to access string name

"it's not" => "it isn't"
"it's" => 'its' if the possessive pronoun was meant
"it's" => 'it is'

[Specification DSL] default_subspecs is only allowed at root level

[Doc] Minor fix & consistent quoting style

For consistency, while there are some places where Ruby requires double quotes.

#targets property doesn't exist anymore.

Podfile DSL Docs improvements

[TargetDefinition] Safe access for bool values

False values were set to nil, when they were read.

[DSL] Rename xcodeproj to project

[DSLError] Dont suggest updating CocoaPods

Fix typo in documentation

[Documentation] Add sample for `:inhibit_warnings => false`

[DSLError] Do not show update suggestion on argument errors

Add ability to disable inhibiting warnings per pod

This enables setting `:inhibit_warnings => false` option to pods in podfile.
Warnings from pods ...

[Dependency] Fix obsolete HEAD string check for lockfile entries

This is needed to handle cases like `HEAD based on 1.0.5` string specifiers.

[Dependency] Allow creating from a string that has HEAD info

[TargetDefinition] Fix whitelisting pods in non-root targets

[Specification::DSL] Remove docset_url attribute

Podfile Refactor

[JSON] Fix platform serialization to handle inheritance

[DSL] improve docs on platfrom attribute for a spec