New: gr-tags without any tags

Signed-off-by: Miroslav Safr <Miroslav.Safr@gmail.com>
New: gr-commits2tag show commits on repositories without any tags with MAX amount limitation
Signed-off-by: Miroslav Safr <Miroslav.Safr@gmail.com>
New: gr-commits2tag,gr-tags header message
Signed-off-by: Miroslav Safr <Miroslav.Safr@gmail.com>
New: configurable flag for max commit count (-mc| --max-commits)

Signed-off-by: Miroslav Safr <Miroslav.Safr@gmail.com>