* build: add cross-compilation support to make
Set CROSS_COMPILE when running make to use the selected cross
compilation toolchain, such as arm-linux-gnueabihf, or
aarch64-linux-gnu.
Testing requires the presence of qemu - 'qemu-$(ARCH)' will be executed,
where ARCH is the first part of the toolchain triplet.
* build: add cross-compilation support to cmake
If C_COMPILER/CXX_COMPILER/CC/CXX are found to have cross-compilation
triplets in front of the compiler, then qemu will be used to execute the
tests.
* CI: add arm-linux-gnueabihf-gcc builder to Travis
The version of qemu available in Ubuntu trusty (as provided by Travis)
appears to have a bug in qemu-aarch64, which leads to the compatibility
tests failing on some inputs, erroneously rejecting the input as
corrupt.
Once Travis supports xenial, we could add an aarch64-gnu-linux-gcc
builder as well.
* CI: propagate cmake errors out of .travis.sh
Seems like even if cmake fails, the error isn't picked up by Travis.
Add some more test cases that decompress to the empty
file or a one byte long file. These test cases have
examples for the updated stream header and meta-block
header formats.
