Merge branch 'fix_1134'

Merge pull request progit#1136 from rpjday/ch4

chapter 4: numerous tweaks, rewordings and font changes

Merge pull request progit#1133 from rpjday/ch3

Chapter 3: numerous pedantic cleanups and rewording

Merge pull request progit#1130 from dfa1/simplify_rakefile

inject version and date using attributes

Merge pull request progit#1131 from rpjday/ch1

chapter 1: minor grammatical/font changes for consistency

Merge pull request progit#1127 from aollier/TortoiseGit

TortoiseGit bug tracker

Merge pull request progit#1124 from aollier/spaces

removed trailing space

Merge pull request progit#1122 from Ignacy-s/patch-1

Change suggested Git version from 2.0.0 to 2.8.0

Merge pull request progit#1118 from aollier/powershell

PowerShell links update

Merge pull request progit#1116 from Tvirus/master

change the describe of when should force the removal with the -f option