Format specifiers in f-strings don't highlight the entire thing in a consistent manner

還沒有人認領這個 Issue。

Hello. Sometimes the `:...` aspect of a format string is highlighted in its entirety but often times it's not. I would like to know if it's possible to make it so it's all under the same consistent scope or if it's by design that it doesn't. My main use case has to do with types using a custom `__format__`.

For example:


I would have imagined both of these to fall under the same scope but they're not.

The first screenshot goes `source.python` > `meta.fstring.python` > `storage.type.format.python`
The second screenshot goes `source.python` > `meta.function-call.python` > `meta.function-call.arguments.python` > `meta.fstring.python`

A regular line of code without using custom `__format__` (e.g. `{test:.2f}`) goes as `source.python` > `meta.function-call.python` > `meta.function-call.arguments.python` > `meta.fstring.python` > `storage.type.format.python` which is what I would expect the other two to return as well, unless it's meant to be treated differently.

* **Editor name and version**: Sublime Text 3.2.1 Build 3207
* **Platform**: Windows 8.1
* **Color scheme**: Custom
* **MagicPython version**: 1.1.1
* **A sreenshot**: See above
* **5-10 lines of surrounding code**: In the screenshot hopefully

首先在使用 MagicPython 1.1.1 的 Sublime Text 3.2.1 中重現兩個 f-string 範例，並檢查它們的語法 scope，將其與一般的 `{test:.2f}` 範例進行比較。當回報案例中的格式指定符獲得一致的 scope，或該行為被記錄為有意設計時，即視為完成。

由索引模型根據 Issue 內容生成。