Implemented Pre/Post Archive Script Events

The script events `pre-archive-cmd` and `post-archive-cmd` can be used
to perform any tasks necessary when archiving the composer project.

This functionality can be used to run unit test or and other build
process before archiving, and can be used to distribute the archive
when completed
Fixed a typo in the doc about github auth
Fix typo in doc
add lib-icu and hhvm
correct small bug, source files aren't installed and removed from the same path (problem with targetDir package attribute)
Merge pull request #2620 from robocoder/patch-1

add hhvm and icu
Merge pull request #2621 from asm89/patch-1

Fix typo in doc
Merge pull request #2618 from stof/patch-5

Fixed a typo in the doc about github auth
Replace %name% with %package% in 05-repositories.md
updated documentation with pre/post archive events
Merge pull request #2629 from moranjk/master

Implemented Pre/Post Archive Script Events
Improved package sorting
Coding style compliance
Correct JSON
[tests] Unit tests for JsonValidationException class
[Archiver] Rules in GitExcludeFilter are too broad
[Archiver] comment for a confusing line
Merge pull request #2647 from thewilkybarkid/invalid-json

Correct JSON
Fix PSR-4 autoload classmap generator
Detect composer install foo/bar misuse and suggest alt