Branch for developing Bitten client/server testing
initial checkin.  Too much work in one step!
Merge in changes from trunk
Account for nonstandard library testing directory structure.
Support for direct XML generation
Clarify and comment XML generation
Roll in Rene's changes from r41174
Roll in Rene's changes from r41182
Dump XML dependency graph
Roll in changes from trunk
Changed XML output to give the actual target name rather
than the high level Boost.Build name.
Merge in some changes from trunk
Make the empty actions for out-xml.generate succeed on Windows
Stop checking out tools_regression, tools_bb, et. al.
Repair NT workaround so it doesn't break everything else
A large checkin (mea culpa)!

regression/src/failure_markup.py:
regression/src/bitten_reports.py:
regression/src/collect_and_upload_logs.py:
regression/src/run.py:
* factor Bitten reporting into a separate module
* Stop hacking the target ids to find source file paths; use a
  slightly more principled approach instead
* support the use of failure markup to ignore test failures

regression/src/test_results.py:
* readability/maintainability improvements:
  * replace tuple representation of build actions with instances of an
    Action class
  * Renamed various attributes to make them more meaningful
* stop hacking the target ids to find source file paths; use a
  slightly more principled approach instead
* add an extremely crude test of this module

regression/src/recipe.py:
* begin taking the toolsets from the slave.ini file

regression/src/regression.py:
* default to no logging at all
* support the use of failure markup to avoid running tests at all for
  particular toolset/library combinations, and to determine failure
  status for individual libraries
* Idiomatic string slitting and joining

build/v2/build-system.jam:
* represent project ids when XML dumping targets
* represent leaf targets ("sources") in the dumped XML dependency graph
* update action rule signatures to conform to the new protocol

build/v2/tools/testing.jam:
* group all XML-dumped tests under a <tests>...</tests> tag
* distinguish a test's human-readable name from its raw target name in XML
* record the project root for each dumped test

jam/test/test.jam:
jam/doc/bjam.qbk:
jam/doc/history.qbk:
jam/src/execnt.c:
jam/src/make1.c:
jam/src/jam.c:
jam/src/execcmd.h:
jam/src/variable.c:
jam/src/output.c:
jam/src/output.h:
jam/src/strings.c:
jam/src/build.bat:
jam/src/build.jam:
jam/src/execunix.c:
* Merged recent changes from trunk
Merge all the latest bjam changes into this branch
Fix msvc auto-configuration (yikes!)
Merge 64-bit support from trunk