remove -std=c89 from default CFLAGS
remove -std=c89 from default CFLAGS

This used to be here to help catch common errors hindering portability to
other compilers (VS6, gcc 2.95, ...), but this breaks compilation against
libusb 1.0 since its headers use the 'inline' keyword. Remove this flag (for
now?) since we need libusb to extract SysInfoExtended from a Nano 5G

hyperair/libgpod,neuschaefer/libgpod,neuschaefer/libgpod,hyperair/libgpod,hyperair/libgpod,neuschaefer/libgpod,hyperair/libgpod,neuschaefer/libgpod,neuschaefer/libgpod,hyperair/libgpod