.version
configure: rationalise error messages with meaningful texts
Currently, error messages just state the obvious: a required
component is required. While in some cases, there is not much
else to say, in some other cases we could tell much more.
For example, a missing libstdc++ means no static toolchain.
Also, format error and warning messages in a similar fashion,
with a {error,warning} intro, followed by the message specified
by the caller.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>