Fix issues if runing in an environment with a Turkish locale

[schlan]

Description

When using LOWER_CASE_WITH_DASHES or LOWER_CASE_WITH_UNDERSCORES as FieldNamingPolicy it could happen that certain fields won't get serialized/deserialized.
I've seen that behavior on devices with a turkish (tr-TR) locale. toLowerCase() uses the device's locale and converts an I into an ı. (JavaDoc)

Example

A field with the name:

...
int lowerId = 8;
....

will turn into:

{ ... 'lower-ıd':8 ... }

Recreation steps

Check out the first commit (299ee89) and run the test with the following JVM flags: -Duser.language=tr -Duser.region=TR

References

https://code.google.com/p/google-gson/issues/detail?id=541
http://docs.oracle.com/javase/7/docs/api/java/lang/String.html#toLowerCase()

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[inder123]

👍
Thanks for the fix.