hoverColumn bug in linechart (and its fix)

[swanandgore]

Hovering over a column in linechart can create tags in unintended places. This is because createColumns() in g.line.js does not work properly - Xs.sort() does not sort in numerical order! This can be fixed easily by writing code that sorts numerically.

[samgrigg]

Example: Xs.sort(function(a,b) {return a-b});

[Louhike]

The fix of samgrigg seems to solve the problem for a lot of persons. Will it be implemented?