[Xcb] [PATCH] v2: Link xcb-util* with -no-undefined

[Jon TURNEY]

I'm not sure what other common linker flags might ever be used, but as
requested:

A series of patches for the split xcb-util repositories adding a variable
XCB_UTIL_COMMON_LDFLAGS to xcb_util_common.m4, and using that in all xcb-util
library Makefiles.  Set XCB_UTIL_COMMON_LDFLAGS to '-no-undefined'.

-no-undefined assures libtool that the library has no unresolved
symbols at link time, so that libtool will build a shared library for
platforms that require all symbols to be resolved when the library is linked.