quvi_version: Add support for QUVI_VERSION_BUILD_CC_CFLAGS

Save, and return, $CC and $CFLAGS via quvi_version with
QUVI_VERSION_BUILD_CC_CFLAGS.

Signed-off-by: Toni Gundogdu <legatvs@gmail.com>
examples/version: Print QUVI_VERSION_BUILD_CC_CFLAGS

Signed-off-by: Toni Gundogdu <legatvs@gmail.com>
Merge branch 'tg/next__quvi_version__build_cflags' into next
configure.ac: Rewrite 6cdebfdf4 using $srcdir and AS_IF

Signed-off-by: Toni Gundogdu <legatvs@gmail.com>
FIX: configure.ac: AS_IF for date(1)

Signed-off-by: Toni Gundogdu <legatvs@gmail.com>