Fix for bug 1196.

This bug would cause the player to jump when jump was assigned to
Space and they closed a dialog with Space. I tested vanilla
MW for behaviour and found that Jump was the only basic input which
MW does not allow when closing dialogs (i.e. if Space is assigned to
move forward, MW will move you forward after closing the dialog).

There were two reasons for the bug:
1) OpenMW GUI does not consume UI events
2) Jump occurs so long as key is down (not only on first key down)

To minimally fix the bug, I made it so that keypress events can be
consumed by the GUI and not passed along to the player control
input manager (1). However, if the player holds space, they will still
jump (as the subsequent key held events will be captured and cause
a jump).

Unfortunately, there is no idiomatic way that I could find in the
OpenMW input manager to perform events only on key down. Instead,
I introduced a variable which tracks whether the jump key has been
pressed for the first time within the current frame (2).

Note: I was initially concerned that limiting the jump event to
KeyDown and not Key Hold would cause issues with swimming,
levitating, or variable height jumping. However, after a bunch
of testing in vanilla MW and exploration of the OpenMW codebase
I could find nothing suggesting the need to capture the jump
key being held.
Update in response to comments.

It turns out I was erroneous about problem (1) in my original commit
message. I thought that in an edge case the OpenMWGUI could both handle
the same event on the frame the GUI was closed. My test for
this was broken. So after brainstorming many possible unsatisfactory
solutions to this event handling, it's luckily not necessary!
1196/1217 fix

Fixes an issue where inputs could be processed by both GUI and
gameplay systems. An enabled/disable has been added to OIS
channels, and OpenMW now disables player gameplay hotkeys when
a GUI element has focus. GUI hotkeys are left enabled.
Merge branch 'master' into bug1196jumpdialog

Conflicts:
	apps/openmw/mwinput/inputmanagerimp.cpp
Fix loading a savegame when some of its content files were disabled

Fixes #1380
Respect CMAKE_INSTALL_PREFIX in the global openmw.cfg

Fixes installing to /usr/local (Bug #1378)
Properly handle exceptions when saving the game

Add message boxes when an exception occurs while loading or saving the game
Fix large size_t being truncated to int
Change CharacterManager to use list instead of vector

Solves a crash when deleting all savegames of a character due to mCurrent being invalidated
Ignore raycasting shapes for weapon collision tests

Fixes dead bodies being in the way when they shouldn't.
Re-enable collision when an actor is resurrected
Show wallpaper when loading a savegame
Fix for dereferencing past end of mGuiModes.
Rewrite journal GUI quest index

 - Use quest names as identifiers, not quest IDs. This ensures that quests with different IDs, but the same name (e.g. A2_4_MiloCaiusGone and A2_4_MiloGone) are merged properly, as they should.
 - Switch display from BookPage to MWList. Handles word-wrapping and scrolling properly.
 - Fixes a bug where the quest index would not be updated when opened.
Fix a crash on exit when projectiles were active
Fix overlapping text in SpellWindow when the window is too small
Rewrite journal GUI topic list to use MWList
Small optimization to ESM::Variant
Fix loading ESX files cleaned with testool (Fixes #1382)
Add missing hasItemHealth for lockpicks/probes (Fixes #1385)