**Steps to reproduce**
* If you go to https://phabricator.wikimedia.org/diffusion/ESFO/browse/master/SemanticForms.php;46d3369c31543ef159c0dc5dbd4460aa001ea6f4$53 and https://phabricator.wikimedia.org/diffusion/ESFO/browse/master/SemanticForms.php;46d3369c31543ef159c0dc5dbd4460aa001ea6f4$60 and https://phabricator.wikimedia.org/diffusion/ESFO/browse/master/SemanticForms.php;46d3369c31543ef159c0dc5dbd4460aa001ea6f4$69
* But if you go to https://phabricator.wikimedia.org/diffusion/ESFO/browse/master/extension.json;46d3369c31543ef159c0dc5dbd4460aa001ea6f4$3
**Actual results**
* You carn't use a defined version in extension registration you have to set it manually.
**Expected results**
* You should be able to use a defined version
for example on how it should look.
"versiondefine:" "Example::Example, "SF_VERSION"
the hook where it is defined and then what it should look for in define.
I am not sure if this way is support in json there may be another way.
Notice instead of using "version" we are using a "versiondefine" instead.
@Legoktm what do you think.
Some extensions such as wikibase do this.
I think proper define support needs to be added.