Added webpack.ProvidePlugin for most used imports

Removed imports of React, connect, PropTypes throughout
Removed the "React" in React.Component/PureComponent

app/javascript/gabsocial/containers/domain_container.js

@@ -1,5 +1,3 @@
-import React from 'react';
-import { connect } from 'react-redux';
 import { blockDomain, unblockDomain } from '../actions/domain_blocks';
 import { defineMessages, injectIntl, FormattedMessage } from 'react-intl';
 import Domain from '../components/domain';