Windows instructions list three ports, not four.
Merge pull request #542 from lehy/patch-2

Windows instructions list three ports, not four.
index.md: properly close img tags
Remove information about abandoned OS X tools,
update requirements.
Merge pull request #543 from dmbaturin/master

[install] OS X section update
Improve organization in install.html

* put all Linux distributions under a first-level item
* put all package managers under a first-level item
* move FreeBSD at the end, as items should be sorted by popularity

Conflicts:
	site/docs/install.md
Add information on OCPWin

* add information on OCPWin in both the "portability" page and
  the "install" page
* I also tried to improve the formatting of the tables and the
  description of other ports.

Conflicts:
	site/docs/install.md
Fix typo in install.md
fix second typo
Replace "Four ports" by "Three ports" for Windows
Merge pull request #547 from lefessan/install-format

Improve organization in install.html
Merge pull request #548 from lefessan/windows-ocpwin

Add information on OCPWin