eclipse: Updated c++ compiler settings

Not sure if this is just a superficial reorganization due eclipse/ADT
plugin version, or if it's significant. Let me know if this breaks your
builds. My configuration:

Eclipse 4.2.1 (Juno)
Android SDK Tools 21.0.1
Android SDK Platform-tools 16.01
Android 4.2 (API 17) rev. 1
Win7-64
eclipse: Dual-, quad-, and eight-core compiler optimizations.

Significantly increases compile speed on multi-core/thread machine.
In eclipse, right-click project->Properties.  Then go to C/C++ Build.
In upper-right corner, click Manage Configurations... and set active
the appropriate configuration for your machine.

Feel free to revert these last two commits if they break the build
process on your machine.