port upgrade when port is not installed

[Ryan Schmidt]

I asked port to upgrade wget forcibly (because I just increased the  
version number locally to so a normal upgrade would not have worked  
because the new version is not in the portindex). I forgot I didn't  
already have the old version of wget installed because I got an  
error, which I can reproduce as follows:


$ port installed wget
None of the specified ports are installed.
$ port clean --work wget
--->  Cleaning wget
$ port -ncuf upgrade wget
--->  Fetching wget
--->  Verifying checksum(s) for wget
--->  Extracting wget
--->  Configuring wget
--->  Building wget with target all
--->  Staging wget into destroot
--->  Installing wget @1.11.4_0
--->  Activating wget @1.11.4_0
--->  Cleaning wget
--->  Fetching wget
--->  Verifying checksum(s) for wget
--->  Extracting wget
--->  Configuring wget
--->  Building wget with target all
--->  Staging wget into destroot
Error: Uninstall wget 1.11.3_1 failed: Registry error: wget 1.11.3_1  
not registered as installed.
$ port installed wget
The following ports are currently installed:
   wget @1.11.4_0 (active)
$


It built and installed wget, then built it again, then tried to  
uninstall the old version which was never installed in the first  
place. If port upgrade is going to break if a port is not already  
installed, it should fail right at the very beginning with a clear  
message telling the user to use port install. Alternately, port  
upgrade could become a synonym for port install if the port is not  
already installed.

I'm running MacPorts trunk @37836.