Allow default mode to be overridden.

[chadvoegele]

Hi,

I currently use a vi mode for Textadept that has a default key mode of 'normal' rather than nil ('insert'). With this diff below, I can override the default mode so I am put in 'normal' mode rather than nil ('insert') mode by using textredux.core.buffer.DEFAULT_MODE = 'normal' in my init.lua. I notice this in particular on file open.

Please let me know what you think.

Thanks! Chad

[rgieseke]

Otherwise "DEFAULT_MODE" is just nil so nothing changes for anyone else, right?

Seems reasonable to me.

[chadvoegele]

Ya, that's correct!

[rgieseke]

Awesome, thanks a lot!

[chadvoegele]

Thanks!