search autocomplete should be case-insensitive

[sabreuse]

It's often worth keeping a distinction between capitalized and uncapitalized wordsets ("polish" and "Polish" are totally different in meaning, pronunciation, derivation...), but that doesn't mean searchers will know in advance that they need to enter capitalized words (or even which form to enter).

[malrase]

Note: this is similar to wordset/wordset#62

[interestinall]

fixed.