[1.7.x] Fixed typos in docs/releases/1.7.2.txt.

* Enlarged the sizes of tablespaces which are created by default for testing

  on Oracle (the main tablespace was increased from 200M to 300M and the

  temporary tablespace from 100M to 150M). This was required to accomodate

  temporary tablespace from 100M to 150M). This was required to accommodate

  growth in Django's own test suite (:ticket:`23969`).

* Fixed timesince filter translations in Korean (:ticket:`23989`).

* Fixed ``timesince`` filter translations in Korean (:ticket:`23989`).

* Fixed the SQLite ``SchemaEditor`` to properly add defaults in the absence of

  a user specified ``default``. For example, a ``CharField`` with ``blank=True``