expressatt: Clean up Samsung device inheritance

* Separate expressatt/apexqtmo from d2lte
* Move apexq/expressatt init scripts to device trees
* Do not dex to /cache
* Split proprietary lib handling between msm8960-common and device trees
* Move express-specific init items to init.target.rc

TODO:
* Figure out what proprietary files are actually necessary, and which
  can be shared with msm8960-common ones

Change-Id: I2eef51b5e3f083e1eb690453c9dacb3fe64089f2