Allow user to escape brackets with '\'

[lookingfora]

Brackets are reserved by the syntax tree parser, but some users (such as myself) want to use brackets in node strings (such as to signify that a value is "virtual").

This will ignore brackets preceded with \ when building the tree, then remove backslashes preceding bracket characters before displaying text. Other backslashes will remain unchanged.

[mshang]

Seems reasonable, but what do you think about making backslash escape everything and not just brackets, with double backslash being a literal backslash, like how it's done in most programming languages?

[MCMCMC]

Seems reasonable, but what do you think about making backslash escape everything and not just brackets, with double backslash being a literal backslash, like how it's done in most programming languages?

I love this app! Please add this functionality to the canon branch! I also need it for tense etc. :)