apps/examples:  Change some *err() message to *info() messages if what was a *dbg() message does not indicate and error condition.

apps/graphics and netutils:  Change some *err() message to *info() messages if what was a *dbg() message does not indicate and error condition.

apps/nshlib:  Change some *err() message to *info() messages if what was a *dbg() message does not indicate and error condition.

apps/platform:  Change some *err() message to *info() messages if what was a *dbg() message does not indicate and error condition.

esp8266 wifi scan tested

Make NSH net-initialization be a configuration option

Signed-off-by: Marten Svanfeldt <marten@intuitiveaerial.com>

apps/examples/ostest: SIG_DFL is no long assignment compatible with the sa_sigaction functin pointer.