add "\" for wordtrig

[yuukibarns]

I think it should not be difficult to add API for configuration of wordTrig, but I don't know how to do it.
When writing latex, I still need to use \ for some uncommon symbols and I have to care about whether it will trigger any snippet, which is quite disturbing.

[L3MON4D3]

Hey :)
I think you can also use condition for this (essentially, do the check you've modified in there), I'm not sure if it's such a good idea to change the definition of wordTrig

One issue with condition is that it's a bit unwieldly, but you can use extend_decorator for this.