ismindex: handle time discontinuities and nonzero start time

The input file may not have consistent start times, stream durations and
chunk durations. This patch at least removes negative durations that
make chromecast unhappy, and correctly sets starting time on chunks so
that the split (or .ismf) outputs match the manifest.

Signed-off-by: Martin Storsjö <martin@martin.st>
configure: Split adding of CFLAGS and CPPFLAGS for hardened toolchain
configure: Disable i686 for i586 and lower CPUs
dca: K&R formatting cosmetics

Signed-off-by: Diego Biurrun <diego@biurrun.de>
dynamic loading of shared faac library
no Werror on implicit-function-declaration and missing-prototypes
custom icon and windows resource
use upstream version tag, my repo is always rebased