Updated status bar to use no border around fields.
Added window list button to the notepad with editor tabs.
Added a workaround for a crash on OSX when the app is closed while
debugging is in progress (ref #89).

The crash appears to be in wxEvtHandler::Unlink, but I couldn't find the
cause for it:
0   libwx.dylib	0x014d2bd9 wxEvtHandler::Unlink() + 51
1   libwx.dylib	0x014d4023 wxEvtHandler::~wxEvtHandler() + 37
2   libwx.dylib	0x0146d7fa wxProcess::~wxProcess() + 84
3   libwx.dylib	0x01074af9 wxLua_wxProcess_delete_function(void**) + 23
4   libwx.dylib	0x0113300d wxluaO_deletegcobject(lua_State*, int, int) + 425
5   libwx.dylib	0x0111f6f2 wxlua_wxLuaBindClass__gc(lua_State*) + 101
Fixed wxwidgets issue with wrong cursor shape over editor (ref #89).
Updated windows executable to show properly scaled icons in the Explorer.
Set 'Courier New' as the default font on Windows.

It turned out that some Windows systems (like XP), don't use 'Courier New'
as the default, and rather use some proportional font, even when
wxFONTFAMILY_MODERN is used, which should pick a fixed pitch font.
Removed reference to a dll no longer used.
Fixed a warning when setting empty working directory.
Fixed About screen to fit on Linux (helps #89).
Updated function list dropdown to fit toolbar on Linux (helps #89).
Removed unused code.
Added linux binaries with support for x86 and x64 (helps #89).
Set 'Courier New' as the default font on Linux (ref #89).