Add case insensitive search for network and ref values in public transport system

This commit adds support to the public transport diagram web application. The commit first takes the network that the user enters and transforms it to all uppercase(as this is how they are stored in the database) and then checks if the ref is a word, and if so, changes the first letter to uppercase and the rest to lowercase.  The Chicago public transport routes use colors as their "line numbers", and they are stored in the database in the format, i.e. "Green", "Blue", "Red", etc. This will prevent users from getting back no results found if for instance they typed in network = "cta" ref = "green". 
Probably network/ref need some additional escaping. I could only find an [approach for boost](http://stackoverflow.com/questions/1252992/how-to-escape-a-string-for-use-in-boost-regex) (=not an option for Overpass API).