add iosamap

[bylh]

add amap(高德地图) support on ios platform

[dpa99c]

Thanks for this PR, it looks like Gaode support will be a valuable addition to the plugin.

Before I accept it, I have a question: according to the iOS app documentation, Sid and Did are required parameters in the URL scheme but I don't see them in your implementation. Does the app still launch correctly if they are omitted?

The following will also need to be addressed. If you have time to add this to the PR, that would be great, otherwise I will get around to doing it as some point:

• The plugin documentation will need to be updated
• It appears that an Android URL scheme is also supported, so it would be appropriate to implement support for Android also.

[bylh]

@dpa99c It can start normal without Sid and did on ios device, I see this question on amap forum, this is the link "http://lbsbbs.amap.com/forum.php?mod=viewthread&tid=18424"

[dpa99c]

Thanks for your contribution - based on your PR I have added support for Gaode/Amap for both Android & iOS.