Modify the test driver and lldbtest.TestBase so that the dumping of session info

now goes into a timestamp-specific directory instead of the previous .session-*
files.

[17:24:34] johnny:/Volumes/data/lldb/svn/trunk $ ls -l test/2010-10-18-16:56:12.935342
total 48
-rw-r--r--  1 johnny  admin  1695 Oct 18 16:56 TestArrayTypes.ArrayTypesTestCase.test_with_dsym_and_run_command.log
-rw-r--r--  1 johnny  admin  1652 Oct 18 16:56 TestArrayTypes.ArrayTypesTestCase.test_with_dwarf_and_run_command.log
-rw-r--r--  1 johnny  admin  2967 Oct 18 16:56 TestBreakpointCommand.BreakpointCommandTestCase.test_with_dsym.log
-rw-r--r--  1 johnny  admin  1648 Oct 18 16:56 TestClassTypes.ClassTypesTestCase.test_with_dwarf_and_run_command.log
-rw-r--r--  1 johnny  admin  1665 Oct 18 16:56 TestClassTypesDisassembly.IterateFrameAndDisassembleTestCase.test_with_dsym_and_python_api.log
-rw-r--r--  1 johnny  admin  3873 Oct 18 16:58 TestFloatTypesExpr.FloatTypesTestCase.test_float_types_with_dsym.log
[17:24:37] johnny:/Volumes/data/lldb/svn/trunk $ 

Also, the dumping happens when a test errored in additioned to when it failed.

llvm-svn: 116778