Note for compiling the phpdocumentor help using the (current) revision 810 of
build.xml:

Use phing 2.2.0 tu build it. Version phing 2.3.0beta1 will not work.

If you used pear to install phing, then make sure, that the pear subfolder
pear/data is also in your php include_path. Otherwise you will get an error
'BUILD FAILED Can't load default task list'.

Note that there is a bug in phing 2.2.0 under windows. To fix it replace
in bin\phing.bat the line
set PHP_CLASSPATH="%PHING_HOME%\classes"
by
set PHP_CLASSPATH=%PHING_HOME%\classes

If you use phing 2.2.0 and fixed the bug calling tools\build>phing generate-docs
should compile the the help to build/tobuild/docs/API/phpdoc/html