[jdt-core-dev] Lowering default severity of field/local variable hiding

["Philippe P Mulet" <philippe_mulet@xxxxxxxxxx>]

In order to see these problems, until UI preference is added, please do the
following to enable them.

1. shutdown Eclipse
2. edit the saved preference file:
<workspace>\.metadata\.plugins\org.eclipse.jdt.core\pref_store.ini
and append the following 2 lines:
------------
org.eclipse.jdt.core.compiler.problem.fieldHiding=warning
org.eclipse.jdt.core.compiler.problem.localVariableHiding=warning
------------
3. restart Eclipse, and rebuild all

Our code should be free of these issues which are usually indicating
potential troubles.