Upgrade to CodeMirror v3.13

From v3.12
Config now includes server name

Config filename now also includes server name (domain and subdomains).
This means you can end up with different config files depending on where
ICEcoder is being used, such as config-localhost.php,
config-mydomain_com.php, config-dev_mydomain_com.php etc.
Also now using CodeMirror 3.13
Ignoring config*.php except config-template.php

To avoid any of the config files ending up in your Git repo
Line height added to previously opened files list

Icons and text previously looked out of line
If our file is |[NEW], prefix selectedFiles[0]

This is so we can pick up where we are saving the new file.
Remove old highlight & save dialog now filename

If we have a new filename and our file is not [NEW], we must be
peforming a Save As.
In this case, establish the old filename and if it's visible, change its
BG & FG colors to the default
Also now set previousFiles when any save happens to avoid previousFiles
still having old filenames
The dialog now wants only a filename in both Save As and New File cases
Condensed code a little here
Updated file to reflect main JS file