Introduces monitoring of multiple files for cache invalidation

* adds composer.lock to default list of files monitored for cache triggering
* adds 'cachetriggers' key to keys recognized by ResourceLoaderBootstrapModule
* adds 'cachetriggers' key to $wgResourcemodules[ 'ext.bootstrap.styles' ]

Change-Id: I32a198f1b6f34d8fa93c4e650cd2f3f6f781c5de
Release Bootstrap 1.1 (+ docs improvement)

Change-Id: I3f5e6e10720ed3bf34e550befdbd5ecbbf63e676
Fix composer.json to have dev-master alias 1.1.x

Change-Id: I525f0bd50595d07bba436e202bb7b98532a583c9
Merge pull request #3 from wikimedia/master

Merge from upstream