Add PHP 5.6 and no longer allow failures for 5.5 builds
Add driver 1.4.5 and 1.5.1 to test matrix

Ensure the build prompt for 1.5.x is answered, similar to what was done in doctrine/mongodb-odm@4fe7d418353ba91cce02401ecc7ef72dece27ed9
Merge pull request #176 from doctrine/1.0.x-travis

Add new PHP and driver versions to Travis CI
Merge branch '1.0.x' into 1.1.x

Conflicts:
	.travis.yml
Merge branch '1.1.x'
Ensure in() and notIn() Expr methods yield BSON arrays
Merge pull request #174
Merge branch '1.1.x'
Respect $options when $server is null in Connection constructor
Merge pull request #177 from doctrine/1.0-conn-ctor

Respect $options when $server is null in Connection constructor
Merge branch '1.0.x' into 1.1.x

Conflicts:
	lib/Doctrine/MongoDB/Connection.php
Merge branch '1.1.x'
Convert timeout option to connectTimeoutMS for driver >= 1.4.0
Convert MongoClient timeout/wTimeout options for driver 1.4.0+
Merge pull request #178 from doctrine/gh137

Convert deprecated MongoClient constructor options for driver >= 1.4.0
Merge branch '1.1.x'