[misc] Remove the hack of mc_instance.

Although it works, it also makes a hell in debugger.
[HTML] Fix error handling in html_init_module().

On some error paths, a OLE32.DLL or EOLAUT32.DLL could be errorneously
loaded even if not used (and never unloaded).
[VS2010] Add IMGVIEW files into MSVC project.
[examples/ex_html] Remove doublequotes from resource names.

MSVC resource compiler treats them as an ordinary char and it becomes part
of the resource name.
[VS2010] Add project for example ex_imgview.
[VS2010] Let MSVC to build all projects as C++.

According to Microsoft, "Build as C" is only for compatibility with old
sources incompatible with C++ and maintaining the (pure) C compiler is not
too high priority for them.
[MAKEFILE] Reorganize goals a bit.

 * Goal 'all' makes also HTML docs and builds examples.
 * Default goal is now 'mctrl' instead of 'all'.
[IMGVIEW] Fix imgview_stream_Clone().
Added multiple item selection support to the treelist control
Minor code cleanups.
[TREELIST] Fix copy&paste errors in trace messages.
Treelist multiselect is now only valid for siblings.  Collapsing selections selects the parent is now restored.  Fix for theme-less flicker on mouse move.
Eliminated extraneous iteration steps.  Fixed Shift key handling.  Selected count now internally tracked rather than calculated.
Renamed multiselect style macro.  Ensure internal selection data is updated on item delete.
NULL checks on selected item in key handling routines.
Merge pull request #10 from ArmstrongJ/treelist-mutliselect

[TREELIST] Merging support for item multi-selection.
[TREELIST] Update MC_TLS_MULTISELECT docs.
[TREELIST] Fix code formatting.
[TREELIST] treelist_do_select_ex: Send MC_TLN_SELCHANGING...

... before clearing old selection. If app. denies to change the selection
we should keep old selction unchanged.
[TREELIST] Rework and fix some bugs in MC_TLS_MULTISELECT.

Changes:
 * Get rid of treelist_do_select_ex().
 * Instead provide more optimized functions treelist_set_sel(),
treelist_toggle_sel() and treelist_set_sel_range().
 * Ignore MC_TLS_SINGLEEXPAND when MC_TLS_MULTISELECTION is in use.

Bug fixes:
 * Fix crash when multi-selecting more root items.
 * If selected item is deleted, change selection before MC_TLN_DELETEITEM
notification, so MC_TLN_SELCHANGING and MC_TLN_SELCHANGED are guaranteed
to come before the deletion notification.
 * If multiple items are selected and one of theme is deleted, ensure
that treelist_t::selected_last is set to other selected item.
 * Clarify and fix sending MC_TLN_SELCHANGING and MC_TLN_SELCHANGED for
multiselections.
 * Ressurect better selection change when deleting selected item without
the style MC_TLS_MULTISELECT.
 * Minor improvements to keyboard handling.
 * When losing the style MC_TLS_MULTISELECT, ensure not more then one item
is selected.