Extend/improve "Diffing Binary Files" section v2

v2:
  * grammar fixes
  * description of img2txt is dropped
[fi] Completed Chapter 2.2
Fail on REXML exceptions

Maruku uses REXML internally to parse the xml/html snippets. But if
the parsing fails, no error are generated and the task does not fail.

Let the REXML exceptions appear when processing a file so as to validate
html snippets also.
Merge pull request #476 from progit/fail_on_REXML_exception

Fail on REXML exceptions
[fi] Translated Chapter 2.3
Merge branch 'master' of http://github.com/jukkah/progit
Merge branch 'master' of https://github.com/progit/progit
Merge pull request #478 from jukkah/master

[fi] Translated Chapter 2.3
[ru] chapter 4: Improve wording in "Git Daemon" section
update typo 注意しなければならいのは ->注意点は
update typo 誰かとかの人 -> 誰かほかの人
Merge pull request #480 from sekaiya/ja2

[ja]chapter 2.4　and chapter 3.5 : update typo
[fi] Translated Chapter 2.4
[fi] Made some improvements in Chapter 2.4
makeebooks with translation of "Figure" for cs
[cs] "Figure" before the fig. numbers replaced by the localized "Obrázek"
[pl] next part of the translation in chapter 7
	[nl] 	Delete english text
		Translation was already done
Merge pull request #486 from dwaddle/master

	[nl] 	Delete english text, translation was already done
Merge pull request #484 from gibas/07-customizing-git

[pl] next part of the translation in chapter 7