disable autocmd on file write

[sim590]

As many people do, I have a some autocommands executing when buffer writes to the disk. I don't see any use case where you would like to keep these autocommands when using this plugin, but I may certainly be wrong. If the user wants to trigger his autocommands, he can simply call :write himself.

If there's a use case for autocommands, I could add a global config variable for supporting both behaviors.

[907th]

Hello, @sim590! Thank you for your commit!
This seems to be a breaking change. May be it should be a configuration option g:auto_save_noautocmd which controls this behaviour?