Spell colour/color properly

[Philip Taylor]

Currently the code and data files use a random mixture of "colour" and "color". To minimise confusion, we should change everything to use one form of spelling consistently. (Which form?) (There may be some other words with similar spelling problems.) (I don't think spelling in comments is worth caring about; only class names, XML element/attribute names, etc.)

[Philip Taylor]

(For consistency with glColorPointer, wxColor, etc, maybe American spellings are better.)

[historic_bruno]

Initialise/Initialize also comes to mind. A search in VS shows 1188 lines matching "color" and 390 matching "colour", maybe relevant if we choose to go with the most common usage. We also use both wxColor and wxColour, so we're not even consistent with library functions :)

[Adrián Chaves]

Changes in this regard to user-visible strings have been applied as per #2185.

[Josh]

Since we already use "color" more often that would probably be the better choice. And, personally, I would prefer "Initialize".

We will need to watch out for causing global namespace conflicts, but otherwise, simple text replacement should work.

[dan_trev]

Attached is a ridiculously large patch that changes all the variable names (with a few exceptions) from colour to color.

The remaining offenders are in strings and/or reference XML entries.

The main exception is that wxWidgets uses colour. So wxColour and wxColourDialog references must remain unchanged. I changed ColourDialog to ColorDialog but that causes some weird color.colour combinations when calling the parent class wxColourDialog and may need removed.

The string renaming need more attention to get right. I did not observe any namespace issues within the variables - the XML could be different (I simply don't know).

[dan_trev]

First pass / learning chance of colour to color