Refactored the man.1 and added missing section

Uses convention from man-pages(7)[1].

[1]: http://man7.org/linux/man-pages/man7/man-pages.7.html
English fixes
Added a test for map a path that has been already mapped
Fixed map a path that has been already mapped
minor #43 Refactored the man.1 and added missing section (alquerci)

This PR was merged into the 1.1-dev branch.

Discussion
----------

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Related tickets |
| License       | GNU GPLv3

Uses convention from [man-pages(7)][1].

- [x] Fixed spelling by a native English speaker, @nylen.

[1]: http://man7.org/linux/man-pages/man7/man-pages.7.html

Commits
-------

fcceaa7 English fixes
226e6a9 Refactored the man.1 and added missing section
bug #63 Fixed map a path that has been already mapped (alquerci)

This PR was merged into the 1.1-dev branch.

Discussion
----------

| Q               | A
| --------------- | ---
| Bug fix?        | yes
| New feature?    | no
| BC breaks?      | no
| Deprecations?   | no
| Tests pass?     | yes
| Related tickets |
| License         | GNU GPLv3

It appears after `setup` that read the `/etc/setup/setup.rc` file with Windows path for the cache directory ([ref][0]).

[0]: https://ci.appveyor.com/project/alquerci/cyg-apt/build/1.0.190/job/4c85isv4adi9e3kl#L842

Commits
-------

72f75cf Fixed map a path that has been already mapped
fea26d7 Added a test for map a path that has been already mapped