Adding proxy that does livereload.js script injection - server mode

Support for Application Server is a new option that can be enabled from the LiveReload Configuration Editor. The users should check the "Enable Proxy Server" option. Then, if the LiveReload server is running, a proxy server will be created each time a JBoss AS server is started. Otherwise, when the LiveReload server is started, a proxy server will be created for each JBoss AS server already started. This means that the order in which JBoss AS and LiveReload servers are started is free. Each proxy server will forward the incoming requests to its associated Application Server. The real benefit comes when the user also enables the "Inject the livreload.js script in HTML pages". In this case, the proxy will processing the result HTML pages and insert the <script> tag at the bottom of the HTML pages. This means that the user does not need to install the LiveReload extension in her browser.