[netbeans] trunk code changes makes new project properties needed for old created project

For whom is following NetBeans trunk code:

I just committed some changes to enabled "deprecated", "unchecked"
option with Scala project, it brings some incompatible issues with old
created projects (via NetBeans "New Project"), to fix it, you need to
open file "nbproject/project.properties", add or change the following
line as:

scalac.compilerargs=
scalac.deprecation=no
scalac.unchecked=no

*** This is not necessary for new created projects ***

BTW, "Generate Scaladoc" action for project works now.

Sorry for the inconvenience.

--Caoyuan