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
Monospace branch names
Monospace branch names
Reviewing translation

to ensure compliance within the chapter, before proceeding translation
Reviewing translation
Reviewing translation
Reviewing translation
Reviewed "Una breve nota su SHA-1"
Reviewing translation
Fixed typo
Fixed typo
Reviewing translation
using 'tích hợp' instead of 'gộp' as translation for merge
Reviewing translation
Reviewing translation
Reviewing translation
Reviewing translation
Reviewing translation