MGR: Fix typos in my commit 70639a7 for using  EVT_LIST_CACHE_HINT instead of EVT_LIST_ITEM_SELECTED or EVT_LIST_ITEM_DESELECTED to immediately detect selection changes in generic wxListCtrl for updating task control panels.
scheduler: support OpenCL/CPU apps in the XML plan class spec mechanism

Previously the scheduler would crash in some cases.
Merge branch 'master' of ssh://boinc.berkeley.edu/boinc-v2
MGR: For detection of list selection and list deselection; trigger on EVT_LIST_CACHE_HINT only for Windows; both EVT_LIST_CACHE_HINT and mouse click events work on Mac and Linux, but EVT_LIST_CACHE_HINT generates far more events than we need, so using mouse click events is more efficient.  Unfortunately, using mouse click events does not work on Windows.
scheduler:
    plan_class_spec: allow to specify <project_prefs_default_true/>,
    in which case a project_prefs_tag absent in the project specific
    preferences of the user is treated as 'true', i.e. as if the
    project_prefs_regex matched.
scheduler:
    plan_class_spec: (re-)introduced a numerical OS version at least for
    Windows and Darwin / Mac OSX. This allows to specify a range for OS
    versions numerically with <min_os_version> and <max_os_version>
MGR: Fix progress bars in Linux CBOINCListCtrl by basing  it on generic wxListCtrl instead of native wxListCtrl.
MGR: Fix compiler warnings.
scheduler: locality scheduler: don't send work if the respected app is deselected
server: add "beta" flag to app versions

Add beta flag to app version table.
If set, send that app version only to users whose prefs allow beta work.
scheduler: compile fix
client: fix bug that caused app_config settings to persist incorrectly

We needed to clear the app_configs and app_version_configs vectors in PROJECT
if app_config.xml isn't there
client, Linux: print to stderr if can't parse /proc/x/stat
update_versions: allow <beta/> in version.xml, to specify beta app version
BUILD: Update vboxwrapper's version to 26087.