Add debug helper js functions

[danielbsig]

There are two helper functions which must be written, to make the implementation of debugging easier:

function DebugGoToLine( file, line ){
// Implementation goes here...
}

This should move the focus to the file (if it doesn't already have focus), and to the line in question. Also, it should display a debugger arrow in the margin.

The second function is:

function ErrorGoToLine( file, line ){
// Implementation goes here...
}

Similar to the first function, i.e. moves the focus to the given file/line, but does NOT add a marker to the left margin (probably not. We might experiment with adding an "error" icon, but that probably won't be necessary). This function will be used if a compiler error occurs.

As you may notice, these two functions have similar functionality, and therefore we could write a function (if it doesn't already exist), which takes care of the common functionality.