bug 700693 - OCSP stapling PSM changes r=bsmith
bug 700693 - OCSP stapling testing r=bsmith
Bug 874132 - Second reland Part 3: Replace uses of apkbuilder with zip and custom debug signing tool. r=jmaher,mfinkle

This incorporates follow-ups including: rename the debug key; check if
key alias exists rather than just testing for keystore existence; set
$(AIDL).

Renaming the debug key works around an un-confirmed JDK bug in
jarsigner, where '-debug' and 'debug' compare the same.