#3 Support variables within alias links

[Alexander Pavlov]

Sorry, previously have commited to features request.

for example, next snippet

!define HOST {somehost.com}
[[click here][http://${HOST}]]

currently converted to
<a href="http://${HOST}">click here</a>

I have prepared patch (using TortoiseSVN) which fixes
this issue to

<a href="http://somehost.com">click here</a>

[Alexander Pavlov]

diff to 27/10/2006 trunk (revision 124)