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
Add API rate limit and two factor authentication doc
added config option to optimize the autoloader always
added information to the docs
changed name of the option to optimize-autoloader
use optimize-autoloader config param in update and install commands
Merge pull request #2599 from dlondero/document-oauth-token

Add API rate limit and two factor authentication doc
Merge pull request #2605 from robertboloc/feature-config_optimize_autoload_always

Added config option to optimize the autoloader always
Fixed a typo in the doc about github auth
Fix typo in doc
add lib-icu and hhvm
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
updated documentation with pre/post archive events
Merge pull request #2629 from moranjk/master

Implemented Pre/Post Archive Script Events
Bail out of the normal 401 handling routine when the origin is GitHub
Test if the 401 was caused by 2FA and ask for OTP if appropriate
Add GitHub OTP to request headers
Trim whitepsace from each argument