Allow a key if it's different from last input key

Hi, I'm a fan of your plugin for months.

I think movements like 'jj' are evil, but those like 'jl' are not evil.
'jl' is more efficient than 'jf{char}' in certain cases.
So, I made vim-hardtime allow a key if it's different from previous key.

One catch is that this makes it possible to type 'jljljl...' :(