spice_common.h provides an ASSERT macro, no need to duplicate it
in many places. For now client/debug.h keeps its own copy since
debug.h and spice_common.h have clashes on other macros which are
trickier to unify.
When using config.h, it must be the very first include in all source
files since it contains #define that may change the compilation process
(eg libc structure layout changes when it's used to enable large file
support on 32 bit x86 archs). This commit adds it at the beginning
of all .c and .cpp files
spice client and spice server shares code from
common/{gdi,gl,sw}_canvas.[ch]. However, while most of the code is
shared, the server code wants a canvas compiled with
SW_CANVAS_IMAGE_CACHE defined while the client code wants a canvas
compiled with SW_CANVAS_CACHE.
The initial autotools refactoring didn't take that into account,
this is now fixed by this commit. After this commit, the canvas
files from common/ are no longer compiled as part of the
libspice-common.la convenience library. Instead, there are "proxy"
canvas source files in client/ and server/ which #include the
appropriate C files after defining the relevant #define for the
binary that is being built.
To prevent misuse of the canvas c files and headers in common/,
SPICE_CANVAS_INTERNAL must be set when including the canvas headers
from common/ or when building the c files from common/ otherwise
the build will error out.
