Add date format property for start/end date filter into Report generator

[asfimport]

@milamberspace (Bug 60115):
The report start/end filters don't allow to specify the Date Format (hard coded).

Add a new report date format property (from SimpleDateFormat) will be useful, specially when the results file is produce with a JMeter machine with another time zone than the report generator machine (need to specify the zime zone in the date format).

Version: Nightly
Severity: normal
OS: All

[asfimport]

@milamberspace (migrated from Bugzilla):
URL: http://svn.apache.org/viewvc?rev=1760268&view=rev
Log:
Add date format property for start/end date filter into Report generator
Add new dedicate section Report/dashboard into changes.xml

#4107

Modified:
jmeter/trunk/bin/user.properties
jmeter/trunk/src/core/org/apache/jmeter/report/config/ReportGeneratorConfiguration.java
jmeter/trunk/xdocs/changes.xml
jmeter/trunk/xdocs/usermanual/generating-dashboard.xml