Add an explicit enum value to the spec for text and icon pitch and rotation

[boundsj]

This implements the solution style spec updates described in https://github.com/mapbox/mapbox-gl-native/pull/6253#issuecomment-244856555

one possible approach to address the special-caseness of these properties would be to add an explicit enum value to the spec like auto or inherit for text-rotation-alignment, icon-rotation-alignment and text-pitch-alignment.

• Add auto enum value
• Set default value to auto

cc @lbud @yhahn @jfirebaugh @1ec5

[jfirebaugh]

Rather than change the value of the "basic" level of "sdk-support", I think we should add a separate key "'auto' value". And support here for rendering arbitrary keys from "sdk-support".

[boundsj]

I think we should add a separate key "'auto' value". And support here for rendering arbitrary keys from "sdk-support".

This is done in https://github.com/mapbox/mapbox-gl-style-spec/pull/493/commits/4b8bfbd0301a822de57934085433dfbb401b1229. I used the expected native platform versions that auto will be supported in. I stubbed js as TBD since I'm not certain how the this change and the next js release that supports it will be orchestrated.

Also, the auto string where present in the doc value gained backticks for the benefit of ios/macos documentation

cc @jfirebaugh @lucaswoj @lbud @1ec5

[jfirebaugh]

https://github.com/mapbox/mapbox-gl-style-spec/compare/symbol-complex-default...symbol-complex-default-alt

• Supports markdown in 1st column
• Custom rows appear after "Base support" and "Data-driven styling"

If you are 👍 please pull into this branch and merge.

[lucaswoj]

Why "Base support" but not "Data-driven styling support" or "auto value support"?

[jfirebaugh]

@lucaswoj This PR doesn't change that; let's not nitpick it here.

[boundsj]

@jfirebaugh 👍 I merged the commits from your branch