Doc rebase: Describe rebase as excluding merge commits

Describe rebase in the description section.

Include a softer paraphrased version from the crytic, well-loved,
but sometimes parodied, Name description, and tell users that merge
commits are excluded by default.

Signed-off-by: Philip Oakley <philipoakley@iee.org>

---

http://article.gmane.org/gmane.comp.version-control.git/217410
http://article.gmane.org/gmane.comp.version-control.git/217495
Doc rebase: describe the priority of published work

Give details of the implied priority in the description section.

Signed-off-by: Philip Oakley <philipoakley@iee.org>
---
wording based on:
http://article.gmane.org/gmane.comp.version-control.git/222581
http://article.gmane.org/gmane.comp.version-control.git/223816
http://article.gmane.org/gmane.comp.version-control.git/217410
http://article.gmane.org/gmane.comp.version-control.git/222763
config doc: add dot-repository note

branch.<name>.remote can be set to '.' (period) as a dot repository
as part of the remote name dwimmery. Tell the reader.

Signed-off-by: Philip Oakley <philipoakley@iee.org>
doc: command line interface (cli) dot-repository dwimmery

The Git cli will generally accept dot '.' (period) as equivalent
to the current repository when appropriate. Tell the reader of this
'do what I mean' (dwim)mery action.

Signed-off-by: Philip Oakley <philipoakley@iee.org>