[eclipse-pmc] API request add setProperty/getProperty to StatusAdapter

[Tod Creasey <Tod_Creasey@xxxxxxxxxx>]

REQUEST
Addition of the following API

StatusAdapter#getProperty(QualifiedName) returns Object
StatusAdapter#setProperty(QualifiedName,Object) voiv
StatusAdapter#TITLE_PROPERTY QualifiedName
StatusAdapter#TIMESTAMP_PROPERTY QualifiedName

GOALS/BENEFITS: 
This API will alllow error reporters to add optional
extra information to a status to be reported by the status handlers. We
currently intend to use it for reporting timestamps and title in our dialogs.

RISKS
None. This is a non breaking enhancement.

Affected bugs
https://bugs.eclipse.org/bugs/show_bug.cgi?id=175257
https://bugs.eclipse.org/bugs/show_bug.cgi?id=173678