Remove horizontal whitespace based smart indentation mode haskell-simple-indent

[gracjan]

Rationale:

• haskell-indentation-mode became reliable enough for general use
• haskell-indentation-mode lost its magic and now has a nice predictable behavior
• simple indent despite its name is also a 'smart' mode with surprising behavior
• people think that simple indent does constant space indentation and this is not true, simple indent tries to be smart
• it relies on whitespace between tokens and Haskell defines token boundaries in a different way
• community effort should be more focused

[ivan-m]

Any particular reason why? There might be people that prefer not to use a "smart" indentation mode and just manually indent/un-indent.

[gracjan]

@ivan-m: I updated my comment to state the rationale for the move. Are you using this mode yourself or were you stating a theoretical question?

[ivan-m]

Just theoretical. I'm happy enough with your justifications (I didn't realise it tried to be smart, and thought it just did indent/un-indent).