enable parallel check of languages

Use parallel to spawn as many subprocesses as possible to accelerate
the tests.
Change Maruku check to fully functional mode

this is cleans up the code.
Force output of Rake messages to stderr
[nl] Replace the word “disk” by its translation “harde schijf”
Fix typos
[nl] Fix capitalisation of one title
Fix typos
Fix typos
Merge pull request #564 from kheyse/translate_disk

Correctly translate the word “disk” in dutch
Merge pull request #563 from kheyse/fix_title_capitalisation

Fix capitalisation of one title to match the style of other titles (in Dutch)
[nl] -dt errors and incorrect conjugation of english verbs in dutch
Change system('ruby makepdfs') to system('sh makepdfs’); Fixes progit/progit#557
changed system(“sh makepdfs”) to system(“bash makepdfs”) because makepdfs is a bash script
Merge pull request #565 from kheyse/fix_t_errors

Fix incorrect conjugation of english verbs 'clone' and 'push' in dutch
Merge pull request #567 from kheyse/rakefile_fix

Change system('ruby makepdfs') to system('sh makepdfs’); Fixes #557
[nl] Replace all occurences of the verb ‘clone’ by its dutch translation ‘klonen’
format latex longtables

Now pandoc uses the package longtable of latex to manage tables. The
default setup does not restrict column width. The explanation column
must be constrained to fit in the page's width.
Monospace branch names
Direct the reader directly to the git-completion download link

This is easier than forking the project.

This closes #537
Monospace branch names