build/core: Build in ISOC++11 mode if possible

Add -std=gnu++11 if the compiler supports it

Change-Id: Ied8b4487263172b678fd2912cfe428187b2edf95
Signed-off-by: Bernhard Rosenkraenzer <Bernhard.Rosenkranzer@linaro.org>
build/core: Add option to disable C++11 bits

Change-Id: I45294e8c19bf7cdf200b45fbd114ccd75c4e3ca9
Signed-off-by: Bernhard Rosenkraenzer <Bernhard.Rosenkranzer@linaro.org>
build/core: Use Linaro gcc 4.8 for androideabi toolchain

Change-Id: I480f66d412969d422efd02dc5790f26b6cbf6446