Merge branch 'release/v0.0.4' into develop
Optimized code in function generateLinePrefix.
Merge branch 'develop' of https://github.com/rogeriopvl/php-nanolog
Fixed method create().

If given a name of an already set instance, return value was a undefined
variable $_instance[$name] instead of self::$_instances[$name].
Fixed method create().

Passing optional parameter $dateFormat to the constructor.
Merge pull request #1 from daniel-melzer/develop

Some bugfixes