Restore LDFLAGS to -O2 and add -Wl,--sort-common -s

O3 is potentially funky, linaro has O2, and THE INTERNET SAYS --sort-common -s is FTW

references:
http://forums.gentoo.org/viewtopic.php?t=67777
https://mail.gnome.org/archives/desktop-devel-list/2004-September/msg00377.html
http://www.akkadia.org/drepper/dsohowto.pdf

-VanirAOSP

Change-Id: Ic69fe56b0473f233f06f8507bf496d8807e5a0f0

Conflicts:
	core/combo/select.mk
Set HAVE_UNWIND_CONTEXT_STRUCT for Clang

Change-Id: I423d650181c6736111e4a5e91ded81c471dd08e1
Signed-off-by: Bernhard Rosenkraenzer <Bernhard.Rosenkranzer@linaro.org>
SignApk: update SignApk to support SHA256withRSA signing

(cherry picked from commit c0581a02ede48007623030c4ce13174ee972cc42)

Change-Id: I6212e0f3a6aa3265b111f0f7348b667af4a668b0
SignApk: add support for EC keys

Change-Id: I09bc0e52fc84ec321b997016a8f97de1bfd2770d
Couple more build flags