Since Autoconf places some important feature flags only into the
configuration header, it is necessary to include it globally to
guarantee a consistent build.
Move the include flags for files in the source tree from
configure.ac to Makefile.am where they belong. Also use
AM_CPPFLAGS instead of CFLAGS/CXXFLAGS to make sure the
files in the build/source tree are always picked up first.
Also, remove the include/libsigrok sub-directory from the
search path, thereby making the <libsigrok/> prefix mandatory
when building libsigrok itself. This matches the convention
already imposed on users of the library.
Output modules are now guaranteed:
- Every option is always given, with the default value if not supplied
by the user, and is the right GVariantType.
- No invalid options are ever passed.
Uwe Hermann
Daniel Elstner
Soeren Apel
Joel Holdsworth
Bert Vermeulen