Support debug symbol

[tmori3y2]

• [x] Support .pdb file for Windows apps
• [ ] Support .dll.mdb file for iOS apps
  • [x] Generate .pdb file for iOS apps
  • [ ] Generate .dll.mdb file for iOS apps
• [ ] Support .dll.mdb file for Android apps
  • [x] Generate .pdb file for Android apps
  • [ ] Generate .dll.mdb file for Android apps
• Cannot use nuget pack -Symbols option because it generates ONLY .pdb file.

[tmori3y2]

• .dll.mdb file for iOS apps
  • ReactiveProperty.Platform.iOS.dll.mdb generated.
  • ReactiveProperty.dll.mdb generated.
  • ReactiveProperty.DataAnnotations.dll.mdb not generated.

iOS class library generates .dll.mdb files of itself and its reference assemblies from .pdb files by default.

• .dll.mdb file for Android apps
  • ReactiveProperty.Platform.Android.dll.mdb not generated.
  • ReactiveProperty.dll.mdb not generated but same as iOS.
  • ReactiveProperty.DataAnnotations.dll.mdb not generated.

Android class library dose not generate .dll.mdb files of itself and its reference assemblies from .pdb files. Android app generates .dll.mdb files of its reference assemblies from .pdb files by default.

Maybe iOS app generates .dll.mdb files of its reference assemblies from .pdb files by default.

Then it is enough to pack .pdb file into package.