[Development] Qml mime types

[Mohamed Fawzi]

Now Qt has several files that use the QML syntax:

* .qml files of QtQuick 1 and QtQuick 2
* .qbs files
* .qmlproject files
* .qmltypes files

I wanted to clean up a bit the mime types for the editor, and introduce q generic "QML syntax" file type.

I began doing it using the current application/x-qml type, but Marc Mutz said that it would be better to register types with iana as they did without too much effort for KOffice.

Indeed registering in the vendor tree (vnd.) seems to be doable, and I think it is a good idea.

I was thinking of registering 
	text/vnd.qt.qml => a file using the qml syntax, subclass of text/plain; charset=utf-8

and
	text/vnd.qt.qml-qtquick (.qml file)
	text/vnd.qt.qbs (.qbs file)
	text/vnd.qt.qml-project (.qmlproject)
	text/vnd.qt.qml-meta-info (.qmltypes)
as subclasses of text/vnd.qt.qml

I would specify that the charset parameter should not be used in conjunction with these types, as they all use utf-8.
This charset consideration respect the new guidelines for text/* mime types, that were done to address the concers that made (for example) application/javascript, or the "better choice", and introduced issues with html and xml.

I would no make the connection to text/javascript explicit, because there are subtle differences that makes that none is a perfect subset of the other (charset & strictness, vs extended syntax), but I am open to reconsider this.

This registration should be done for qt, so I am opening the discussion about them here, and when we have a consensus the proposal can be done on ietf-types at iana.org, and then officially registred at
	http://www.iana.org/cgi-bin/mediatypes.pl