DexOpt anything on /system in /cache/dalvik-cache

Change-Id: Id41d37047f2fcb90d513ac091dfcb85492473689

Allow property to disable dexopt on /cache

Change-Id: Ic74707c4bead387bbf82e4c6d5037efc2d2ebeaf
installd: Delete cache properly for devices using datadata partition

The java side already checks /data/data for free space but installd
still checks /data causing it to never reap the cache (because it
thinks that enough free space is available.)

Change-Id: I736af6ff7ea0c8ae07900168f6b8ac2f7a4dbe0b