Per docs added in I18767cd809f67b, these don't need normalization
as they are only compared against predefined strings, and besides
are generally entered manually in a form, and even then would not
require the kinds of Unicode chars that have multiple/non-normalized
forms.

In nearby areas to also fix some trivial cases:

* getVal('title') obviously needs normalization.
  Use getText() to make this more obvious.

* getVal() compared against simple string literals within the code
  obviously don't need normalization (e.g. printable === 'no').

* Change hot code in MediaWiki checking for whether 'diff' or 'oldid'
  are set to getCheck (which uses getRawVal) instead of getVal.
  As a bonus this means it now handles values like "0" correctly,
  which could theoretically have caused bad behaviour before.

Change-Id: Ied721cfdf59c7ba11d1afa6f4cc59ede1381238e