build: Introduce project pathmap and use it for qcom variants

The project pathmap tracks the path to the top level of a project.  The
following functions are provided:

 * project-set-path adds an entry.
 * project-set-path-variant adds a "variant" entry.
 * project-path-for retrieves an entry.

To use as a guard in Android.mk:

  ifeq ($(call my-dir),$(call project-path-for,projectname))

To use for include paths in Android.mk:

  LOCAL_C_INCLUDES += $(call project-path-for,projectname)/...

Set project pathmap for qcom project variants.

Change-Id: I8dceca72a1ba80fc7b1830c5ab285d444f530457
build: Add "dtbs" target when building the kernel

 * This is needed for 3.10

Change-Id: I4044ea9e67017452efc25097a3327141a6627c24
build: Set QCOM variants for non-QCOM_HARDWARE defined targets

* Nexus devices and others typically do not define the QCOM_HARDWARE
  flag, so the variant path should always default to the AOSP variant.
* Unconditionally set the variant to the AOSP HAL by default.

Change-Id: I714170897128f92718af266366cfcbf3136e8981
build: Use project pathmap for recovery

Change-Id: I6339ac77b899a43db21261d587252b65cb58ad79
build: Fix pathmap derp

Change-Id: Ic6070a87fb552b60e761c6dd9c515b7785ea49cb
Revert "Add the keys I used to sign the market version of Superuser."

These are obsolete.

This reverts commit 0f15d18a50d721faa8dee67f763405354025e25a.

Change-Id: I645686c5049f8651e99c95f2b775aaae2cca1f3a
Merge remote-tracking branch 'cm/cm-11.0' into cm-11.0-sgt7