Fix one small issue with .pk3 sorting – ‘.pk3’.

Its presence throws off the intended sort order, so it has to be
(temporarily) removed while sorting the .pk3 file names.
client-input/cmd: remove Cmd_AddButtonCommand

It was used to do +-commands, made a proxy command to handle that.
Also it reduces coupling between cmd.c and cl_input.c
Handle the case where no files in main/ are updated.
cl_input: fix 5b1d28cc0
Fix blur glsl shaders and make them independent of the screen resolution

We were not taking the full number of texture taps previously
Reduce the default value of r_bloomBlur

Higher values cause ugly blur artifacts
Fix bloom
‘Fix’ building shadows with cg_Shadows < 2.
Add fast shadow blur for variance shadow maps

One of the advantages of variance shadow maps is you can use a simple blur filter over the texture for a cheaper PCF-like effect
Fix potential shadow casters being light frustum culled
Fix backside culling for shadow blur
Fix atan/atanf in qvms
Tell travis not to do builds on some branches.

In the case of engine-upgrade, this can be reverted once travis uses
new-enough gcc & clang.
Make +commands work properly on key-up.

This is done by making use of the stored key-down information for the
+commands to determine which -commands are to be executed when a key is
released.

The key binding is no longer used on key-up and is not modified on key-down
(though a few extra commands are executed).
Clear button activations when registering button commands.
Sort surfaces before creating the world vbo

Also ignore surfaces that require CPU deforms because we won't use the vbo in that case
Don't needlessly transpose the tangentToWorld matrix

In glsl, v * mat is equivalent to transpose( mat ) * v
Don't try to load or save compiled shaders if no binary formats are defined.
Move the key-down clearing into a separate function; call it when initialising cgame.
Add a mechanism for non-button +commands to trigger key-up handling.

When executed, a +command must call a function, either trap_PrepareKeyUp()
for cgame code or IN_PrepareKeyUp() for client code.

Conflicts:
	src/engine/client/client.h