[Feature] dSYM parser add multi dsym support

[icyleaf]

This is a feature and also a breaking changes.

AppInfo::DSYM class move mostly of methods to a new class named AppInfo::DSYM::DebugInfo, and use .files method iterater the value.

Example

Get dSYM object, release_version etc

Before

p = AppInfo.parse('dsym.zip')
p.object             # => 'AppInfo'
p.release_version    # => '1.0'

After

p = AppInfo.parse('dsym.zip')

# Get all dSYM debug info file
p.files                # => [<AppInfo::DSYM::DebugInfo>, <AppInfo::DSYM::DebugInfo>]

# Or use iterater
p.each_file do |file|
  p.object             # => 'AppInfo'
  p.release_version    # => '1.0'
end        

More examples to review spec/app_info/dsym_spec.rb file.