backport 44936fd to other language and pdf

This change needs to be backported to all languages. The pdf toolchain
processes this formula with a transformation to some latex mathematic
typesetting and therefore needs to be updated.
[de] Drop trailing spaces
[de] Apply changes from 'en' original
add 03-git-branching
update to 3-8
finish 3-1
Update 01-chapter3.markdown
Update 3.2
3.2 word error
chapter 3 finished
add Chapter 4
chapter 5 finished
Merge pull request #697 from ya-hsiung/master

add zh-tw chapter 3,4,5
Merge pull request #694 from progit-de/master

Update 'de' locale
Update 01-chapter2.markdown

Update line 503 and 522
Update 01-chapter1.markdown

修改错误拼写 Frenode -> Freenode
Merge pull request #699 from haway/master

[zh-tw] Update 01-chapter2.markdown
Merge pull request #700 from iahu/patch-1

Update 01-chapter1.markdown
Update 01-chapter9.markdown

correct the type mistake in the last line of section9.3
Merge pull request #701 from fuzhli/master

Update 01-chapter9.markdown