Fix for compilation with VC++ 2005.

Less liberal use of the "typename" keyword in the templated function.
Merge pull request #8 from Gaerzi/master

Fix for compilation with VC++ 2005
Aspect ratio correction, and Ctrl-Z to editor.

- Added aspect ratio correction checkbox to Gfx viewer and texture
editor. This stretches images vertically by 20% to give a preview of
in-game proportions for certain types of graphics.
- Undoing will now first query the entry panel first. For now, only the
text editor has a built-in undo feature.
- Text editor no longer allows to undo loading the entry...
- Init opened time in SLADEMap's constructor so that SLADE will not
randomly query to save a nameless map when quitting without having
opened the map editor at all.
- Updated a bit stuff.txt.
Merge pull request #9 from Gaerzi/master

Aspect ratio / Undo / misc bug fixes
SVN r1416 update

- Fixed crash when logging an empty string to the console, which
happened notably while logging ACC's output.
- The texture editor's context menu now shows the same export submenu as
the Texture menu for consistency.
Merge pull request #10 from Gaerzi/master

SVN r1416 update
Highlight support for generalized line specials

- Boom's generalized line effects now highlight affected sectors and
affecting linedefs as expected. This is done by having a dummy action
special stored in the game configuration class that is returned when the
special type is within the range occupied by Boom's generalized specials
and Boom extensions are used.
Distinguish between manual and switched genlines

Duplicate the dummy Boom generalized specials. One of them is for
"switched" specials (affect tagged sector), the other is for "pushed" or
"manual" specials (affect back sector).
Merge pull request #11 from Gaerzi/master

Highlight support for Boom's generalized line types
Do a 'full' remove of detached sides/sectors on opening a map, should fix issue #14
Initial work on object edit feature, doesn't really do anything yet (default key 'e')