Merge lp://qastaging/~mterry/unity-scopes-api/turkish into lp://qastaging/unity-scopes-api

Fix reading scope metadata in a Turkish locale.

I don't know of any existing bug symptom caused by this. I came across this while investigating a crash due to a misconfigured locale.

We're using std::locale("") to handle lowercasing user-input (well developer-input) scope metadata keys into standardized key names. This has two effects:

1) If the environment-specified locale is not set up correctly, an exception will be thrown. Fair enough I guess, but still a harsh possible side effect of just trying to lowercase some ASCII characters.

2) Using a locale-sensitive lowercasing algorithm has some odd side effects. Most notably in Turkish. See [1] and other such sites if you google "turkish i problem." Basically, if your problem domain is ASCII and/or you are not dealing with strings that the user will see, you probably don't want to be converting characters with the user's locale.

I've added a test that demonstrates the issue. With the old code, if you don't have the tr_TR.UTF-8 locale installed, the test will crash. If you do, it will fail. With the new code, it will pass in both cases. I've added language-pack-tr to the Build-Depends to make sure the locale is valid during normal build tests (the i problem is more interesting to test than the invalid locale problem, which is probably expected behavior anyway).

[1] http://haacked.com/archive/2012/07/05/turkish-i-problem-and-why-you-should-care.aspx/