Bug 535344 - Replace StringBuffer with StringBuilder

Similar to Bug 533897 for JDT.UI we should do the same for jdt.debug
Only remaning usage is in ImportBreakpointsTest.java as
ImportBreakpointsOperation uses it in its constructor.

Change-Id: Ieabad25edbe73e9395bf283fe8628b24861232cd
Signed-off-by: Lars Vogel <Lars.Vogel@vogella.com>
93 files changed