Remove unused project external/libppp.

Bug: 16795898
Remove external/icu4c and add external/icu to the PDK.

Bug: 16891889
Remove external/xdelta3 and external/syspatch

BUG: 17299918
Change-Id: I080399c35ea62f1e40dca32728a7c9e3ca57795c
Remove Chromium's copy of OpenSSL.

Chromium now uses boringssl instead of openssl; remove the
no-longer-maintained copy of openssl.

Change-Id: Ic923b036c70dcfbaa374ea187badb76e76422935
Add platform/external/chromium_org/third_party/libjpeg_turbo
Add platform/prebuilts/gcc/linux-x86/arm/arm-linux-androideabi-4.9
Add platform/prebuilts/gcc/darwin-x86/arm/arm-linux-androideabi-4.9