Deprecation/Removal: usages of from_deprecated_string and to_deprecated_string

[Diana Huang]

Hi there,

We plan to deprecate and remove usages of to_deprecated_string and from_deprecated string from edX repos. We are targeting removal after March 5, 2019.

Please read https://openedx.atlassian.net/browse/DEPR-16 for more information and to post any questions/comments. The proposed deadline for comments before acceptance is Feb 19, 2019.

Thanks,

Diana Huang