Tidy: Various source files and entries in project files.

Renamed exittreewidget and glwidget files to camel-case exitTreeWidget and
glWidget respectively in repository, usage locations and mac_src.pro &
src.pro project files.

Rogue dlgTriggers_main_area.h removed from repository, mac_src.pro and
src.pro files and missing dlgTriggersMainArea.h file-name (present in
repository) added to both mac_src.pro & src.pro files.

XMLimport.h and XMLexport.h file-names, missing from both mac_src.pro and
src.pro files added to them.

Missing console.ui, filters_main_area.ui, help_dialog.ui,
options_area_filters.ui, set_room_area.ui, delete_profile_confirmation.ui
file-names added to mac_src.pro & src.pro files.

Added /usr/local/include to unix:INCLUDEPATH and moved -L/usr/local/lib to
front of unix:LIBS so these locations are available / used as per Linux
FHS.

Duplicate of Mudlet_splashscreen_main.png without extension removed.

Mudlet_splashscreen_main.png trimmed of a couple of transparent pixels to
top and right of image. Also version number text erased in preparation
for new code that paints version number in as Mudlet starts up.

Files not mentioned in mac_src.pro added to that file in the corresponding
place: TRoomDB.cpp & .h, TVar.cpp & .h, dlgPackageExporter.cpp & .h,
dlgVarsMainArea.cpp & .h, exitsTreeWidget.cpp & .h, LuaInterface.cpp & .h,
VarUnit.cpp & .h .

Absent luazip.c file removed from mac_src.pro.  Duplicate TMap.h entry
removed from both mac_src.pro and src.pro.