Create option to only load vim confs once per session

[jenterkin]

g:autosource_load_once_per_session

should default to 0

when set to 1 a given vim conf should only be loaded once per session

[zeertzjq]

Should this be limited to autocmd only, or also apply to :AutoSource?

[jenterkin]

Good question. I don't think it should apply to :AutoSource since if you're running that command you probably want the conf to be sourced :p

I should have included this in the description, but the motivation here is to not source the same files over and over when moving around since you could have some weird side-effects depending on how you write your confs.