Master-Slave support using named registration

Changes to the autofac version so that ISolrOperations,
ISolrReadOnlyOperations were registered by name (core id). This is to
support seperate cores for master and slave and to have the same
document type. Currently only one instance of ISolrOperations for a
particular document type could be registered with the container.
Merge pull request #2 from sdharmaraj/master

Master-Slave support using named registration