Bug 542704 - Breakpoint not enabled when adding from Stack Trace

- in JavaExceptionHyperLink.linkActivated(), for an existing
  exception breakpoint, default enablement to true and save
  original enablement value to reset if user cancels property dialog
- add new ATTR_ENABLED_SETTING_ON_CANCEL attribute to JavaBreakpointPage
- in JavaBreakpointPage.performCancel() reset enabled setting back to
  original if ATTR_ENABLED_SETTING_ON_CANCEL is set
- in JavaBreakpointPage.performOK(), reset
  ATTR_ENABLED_SETTING_ON_CANCEL attribute to null
- add new test case to LineTrackerTests

Change-Id: Iea8abc9279776bcefae83b7af6efc355016b91ec
Signed-off-by: Jeff Johnston <jjohnstn@redhat.com>
3 files changed