Build failure on Travis / Mono - $(ProjectName) is blank
Build failure on Travis / Mono - $(ProjectName) is blank

It looks like the $(ProjectName) variable is not set up correctly in mono xbuild.

Failure mode:

https://travis-ci.org/jthelin/ServerHost/builds/101178055

```
Target AfterBuild:
    Executing: xsltproc -o ../documentation/.md ../documentation/DocFormatter.xsl bin/Debug//.XML
    warning: failed to load external entity "bin/Debug//.XML"
    unable to parse bin/Debug//.XML
/home/travis/build/jthelin/ServerHost/ServerHost/ServerHost.csproj:
    error : Command 'xsltproc -o ../documentation/.md ../documentation/DocFormatter.xsl bin/Debug//.XML' exited with code: 6.
   Task "Exec" execution -- FAILED
   Done building target "AfterBuild" in project
```

jthelin/ServerHost,jthelin/ServerHost